I posted a few days ago about an issue I am having with this Interarms Mark X (mauser action) I just purchased.

I used some middle of the road to close to max hand loads using IMR 4350 and H414 powder with Hotcor 180 gr bullets. The bolt was somewhat difficult to open and my velocities were higher than they should be. I then shot some power point Winchester factory 180 gr rounds and they shot around 2800 with no pressure signs. I openly am aware of my dumb mistake to start with loads in a new rifle (at least new to me).

So I went back to the range with new hand loads and worked my way up from the minimum suggested grains using H414 and IMR4350. When I got to 51.5 grains of IMR4350 and also at 51.5 grains of H414 I started having pressure signs only in the form of a sticky bolt. I checked for primers flowing, extractor marks and nothing, only the hard to open bolt. On those shots, the bark out of the gun did seem louder than normal and the last one did have an extractor mark. This was also in temps today in only the upper teens which in the past has affected my velocities downward and I would assume pressure should be a bit less also in these colder temps.

I then shot 180 gr Winchester power points (factory loads), fairly accurately with no pressure signs at all.

I am just starting to wonder If I should just shoot factory rounds in this gun. I have loaded for several guns over many years and never before have I had a gun or brass show these pressure signs and thus I have never been afraid to hand load for any of them. I am getting afraid to hand load for this one. Whomever put this gun together must have not had much tolerance built into it. I bought it at Cabelas as a used gun and with a 26 inch barrel and an after market stock it appears to be custom made with just the Interarms amuser action.

Any advice? Should I just shoot factory ammo in thus one? And also, isn,t it interesting how my hand loads show pressure signs, even at likely less velocities, than the factory ammo.

I think at this point I'd start by calibrating my scale. roger

Yeah, that is what I am thinking also since everyone of these loads was hand measured. Thing is I use a powder measure also and at least with h414, which is an easy powder to meter, all of the loads were measuring out consistently. And also during this same time period I have loaded for three othe rguns and shot them also with no issues. All of these factors point me to think this may just be a difficult gun.

I don't understand the problem. All rifles will show high pressure signs past a certain point. Then reduce loads so they are below that point.

The reloading manual does not tell what pressure and velocity you will get. It only reports what pressure and velocity THEY got, in THEIR rifle, etc. You aren't "supposed" to be able to use their max loads.

Bruce

Are you using a chronograph at the range?

I am using reduced loads that are right around the minimum that my manuals are stating. I guess maybe I will have to go below the stated minimums. I guess if I use some loads that are less than the stated minimum and find that they get decent velocities all will be fine, but based on my past crony results with this rifle, these crony results with these low loads will likely not be very decent. I don't need awesome velocities but if I have factory loads that shoot 2775 gps accurately with no pressure signs (180 gr), and if I finally find hand loads that are safe and show velocities of 2500 gps it's just not a real exciting prospect to hand load for this rifle.

What caliber?
Well, it's a custom job, so it's hard to say how the chamber was cut. I'd check to see if it was short throated, and maybe cast the chamber to see if it's jugged.

Maybe this problem is why the gun was sold in the first place?

I think you must be missing another variable. Something doesn't add up. If factory loads are giving you X velocity with no pressure, you should be able to get to similar speed without pressure with your reloads. If this was one of the new Ruger or Hornady special carts with the 'magical' powders they are using, I might say you are up against the wall, but this isn't the case. I am wondering if your case sizing is sufficient, or if your COAL is funny or something. I will say that I have a few rifles I don't shoot a lot that factory ammo did fine in, so I shoot factory in them, but I KNOW that I can closely replicate these factory loads if I need too.

Keep us posted and good luck.

That's what is odd. The factory loads are giving me almost 2800fps with 180s, just standard Winchester power points, with no pressure signs but when I shot under the crony two weeks ago, h414 at 53 gr with velocity at 2750, bolt hard to open. I try reading primers but honestly my chrony seems to be more effective in identifying pressure. All I know at this point is that it seems imr 4350 and h414, my go to powders for the 30-06, are giving me pressure signs with velocities at least 100 fps less than factory loads and are even giving me press signs with loads that are hovering a close to the starting loads, so maybe I need to try different powder for this rifle. I am loading for other 30-06s right now through full length re-sizing like all always do with no problems in those rifles. This particular gun is presenting me with some challenges.

Being a used rifle you might want to have a gunsmith check it out. I bought a remington 788 in 22-250 that would blow primers with factory loads.
I took it back to the gunshop where I bought it. The gunsmith there tried several thing to fix it. They finally sent it back to Remington. They said the chamber and throat was rusted up. They set the barrel back one turn and rechambered it. After that no problems. Most anything I shot out of it worked well. Factory, hanloads. One thing I found curious was everything shot real close to the same point of impact at 100 yards. 50 gr to 63 gr.

Hard bolt lift, or sometimes called a click can be from a tight chamber in the web area,not pressure. Try changing the brand of brass and bullets. You may have some extra heavy brass. The bullets might have a long bearing surface or thicker jacket, all can make more than normal pressures. I would need a few more pressure signs other than 1 extractor mark.

Also, take measurements of a loaded factory rounds neck diameter. Fire it. Has the neck diameter expanded by .002" or more. If so you are OK in that Area.

Make a chamber cast,, that will indicate condition of chamber and also ypu will be able to take all chamber measurements. There is a possibility that you have an extra tight chamber, which would require more reaming.

quote:

Interarms Mark X (mauser action)

Is it for sale?

I had a 264 (have) that I bought, it would fire factory ammo fine but would not chamber reloads without more pressure on the bolt than I find comfortable. after 3 sets of dies (i have since learned more about troubleshooting gun stuff, but the first two sets were used and I thought both might have had a problem) I sent it off and found out the neck was tight, I didn't want to neck turn brass so had it taken care of. chambers reloads fine now.

that was first i knew of commercial ammo being slightly under dimensions, apparently to compensate for chambers like mine.

Red

Check case length....... and can you insert a bullet into a fired case?

If not, then the case is too long or neck too tight.

Could the bullets on the hand loads be jammed into the lands? This can cause higher pressure. Factory loads are typically way off the lands.

The brass should be fine because the same brass was used in reloads that were shot in two other 30-06s within the last couple weeks with no issues. The brass was once-fired from recent factory load firings. The only thing I can point to is what the previous poster just wrote, that the reloads are pushing into the lands. I tested some dummy reloads in the gun and found that the bolt would't close with rounds that weren't much longer than the actual reloads I was using. This gun has a very short chamber compared to my other guns. Also my actual reloads that were fired and caused the pressure issue are significantly longer than the factory rounds which fired fine, even though they would still chamber ok. So my only conclusion at this point is that my reloads are pushing up into the lands of this particular rifle and thus causing pressure increases. Seems odd because I have shot reloads in other rifles where the bullets were seated fairly far out, approaching the lands with no issues but maybe this rifle has just really tight tolerances.

You need to check the OAL of the cartridge with your bullet against the throat length of your rifle. Not hard to do.
One way -- Take a fired case, size it, cut a slot down the neck with a dremmel tool. Put a bullet in the case - barely started - then cycle through the action. The bullet will hit the lands and be pushed back into the case. The result is the Over All Length where the bullet touches the lands. Run several bullet through to get an idea of the OAL. Sometimes the bullet will stick in the lands and you have to push out with a cleaning rod.


You also need to measure the case length after resizing to make sure it's not too long. As Terry mentioned - too long and the case mouth gets into the throat area - pinches down - and pressure goes up.

One other thought - and this is out there.
What bullets are you using? Could they be .311 diameter?

It could be that the locking lugs have been
set back. Remove the firing pin and ty to
open the action while putting force on the bolt
with a rod.
Good luck!

Good thought that Trigger has above. I had a Browning 264 Win mag at one time that had vertually "no" throat, and gave terrible pressure signs.

A few twists of a throating tool solved it all.

quote:

I am just starting to wonder If I should just shoot factory rounds in this gun.

A sticky bolt is likely the most reliable sign of an overload we can have!

Factory loads shoot fine but your hot reloads don't? Sorta makes one think your reloads are TOO hot? But, with no clue to the cartridge you're shooting in "this gun" I have no clue what to suggest.

There is little value in starting low before moving up if we're going to ignore the warning signs we encounter and keep going up anyway. ?? IF you're gonna do it that way, stick to factory stuff!

CHECK YOUR POWDER SCALE...AND BUY A CHRONO...also buy a set of Hornady headspace and bullet overall length gauges.

Having a chrono will tell you...FOR CERTAIN(within a given certainty) just what the velocities actually are...until you do this you are whizzing in the wind...and powder scales can get knocked out of spec very easy AND digital scales can weight plus or minus 2-4 gr out of whack also.

In the olden days and something I also do for factory standard calibers it to fire a few factory rounds over the chrono for the velo and then mic the cases all over...base, shoulder to base, neck expansion, neck ID, wall thickness etc...THEN start load workup with new cases.

All the pressure/load parameters could be found for the factory most of the time and most were loaded to SAAMI specs. I could then use that data as a baseline for developing my own loads.

Most of the time, FOR FACTORY STANDARDS ONLY, for a SAAMI minimum reamer spec'ed cut chamber, the velo and pressure signs would be very close to what the factory ammo produced. NOT so with wildcat chambers or a "lousy" gunsmith cut chamber.

You have much more control over all the adjustments in your reloading tools and loaded ammo parameters by "rolling your own" than you do with factory ammo.

Most factory ammo is made to fit EVERY chamber from too long to too short so that should give you a clue that your chamber might not be precisely SAAMI spec. The Hornady gauges will give you that information.

I've had pressure spike problems with H414 several times in the past with several rifles so I don't use it anymore, I use AA2700 or RL-17 now. IMR4350, H4350 and AA4350 all have DIFFERENT burn rates but USUALLY will show a progression when it comes to pressure...very seldom any pressure spikes.

If factory loads shoot fine and YOUR loads DON'T then there is something radically wrong with your reloading proceedures somewhere. Break out you calipers and mic and start measuring everything there is to measure on several of your reloaded cartridges AND the fired case that gave you the most problem.

Everyone on this thread gave you some very good information and things to do. You might try working through them to find a solution.

As bcp and Jim alluded to...EACH rifle is just as different as each persons face if you saw it on a thread...what works for my rifles most likely won't work for yours except in a very limited way.

You might also do some research...your problems are pretty common and this forum is full of very good solutions.

Luck

I have to agree that something is radically wrong here. problem is I'm not exactly sure what it is. Near as I can figure, the gun is a 30-06 shooting 180 gr. factory ammo from a 26" barrel with no problem, but reloads show high pressure/ What bothers me, and no one has seemed to mention it, but 2800 FPS from factory 30-06? A while back I did a chronograph test shootin 180 gr. Winchester Silvertip ammo from three rifle, one each 22", 24" and 26". Only the 26" gun came anywhere near advertised velocity of 2700 and even that was 50 FPS shy of the mark. Thinking maybe it was that particular rifle, I re-shot that ammo in another 26" barreled rifle with very similar results. (Both rifles were Ruger #1B.) That second round didn't do much better as I gained a whole 10 FPS average from the second rifle.
Someone mentioned a chamber cast and that's a good idea I'm thinking but I am also thinking the bore should be slugged as well. overly tight bore? The thought that he might be using the wrong size bullets is a thought. A while back I was loading 140 gr. bullets for my 7x57 and had several bullets just drop through the neck. Turned out they were 25 caliber bullets. Mistakes can happen. Regardless, I am troubled by the higher than expected velocity from the factory ammo.
It's damned hard to diagnose a problem over the internet. Let's hope it ends up being something simple to square away.
Paul B.

quote:

Near as I can figure, the gun is a 30-06

Yeah, near as I can tell too. But guesses ain't nowhere near good enough to make serious appraisals or suggestions, is it?

Well, I calibrated my scale by checking at using various bullets and it is right on the money. The brass I used for these reloads that came out "hot" was all trimmed to the minimum size and measured with a caliper and full length re-sized. Also, this brass was used in reloads that were fired in two different 30-06s and shot during the same shooting session with no issues. I also took advice from a previous post about this gun having a tight neck and tested placing a bullet into one of the fired cases from one of the rounds fired in this mauser and they didn't fit right in very well, some took a little umph to get them in, but that test doesn't seem very conclusive because I got some 30-06 brass from another fellow at the range that day(factory loads that he had just fired) and putting bullets into those fired cases was also difficult. I am meticulous about my handloading process and have never had any issues up until sattempting to load for this Interarms 30-06 mauser.

Like I said in a previous post, "I tested some dummy reloads in the gun and found that the bolt wouldn't close with rounds that weren't much longer than the actual reloads I was using. This gun has a very short chamber compared to my other guns. Also my actual reloads that were fired and caused the pressure issues are significantly longer than the factory rounds which fired fine, even though they would still chamber just fine. So my only conclusion at this point is that my reloads are pushing up into the lands of this particular rifle and thus causing pressure increases". This is the only thing at this point I can hang my hat on.

When the weather gets better out, a blizzard up here right now, I am going back to the range and will try the minimum stated loads 51 grains of IMR 4350 with 180 grain rem core lokts and 50 grains of H414 with the same rem core lokts and seat the bullets in to match the OAL of the factory cartridges that shot fine with no pressure signs.

If I don't notice any pressure signs I will work up slowly from there, but honestly, the pressure signs were showing up last time(bolt hard to open) with only 51 gr of H414 and 51 gr of IMR 4350, which is a very mild load. This time I will have my chrony with me and measure the velocity of these mild loads. Hopefully what I find is that by seating the bullets at the depth so the reloaded cartridge matches the OAL of the factory cartridge that I can work up some loads to a satisfactory velocity and good accuracy without pressure signs. If I reach any pressure signs with these "bullet seated deeper" reloads and the velocities(looking for at least 2650 fps) and accuracy(would like to achieve consistent 1 1/4" groups) aren't decent enough, I will be taking the gun in to a gunsmith to measure the chamber and diagnose what is happening. I don't want to spend the money for that but I also don't want to just shoot factory loads in this gun, and damn, it is a nice looking and very clean gun.

Thank you everyone for all of your help. There has been some very, very good advice given in this post. I will let you all know what I find out at the range and if needed, from the gunsmith.

Well, after reading the post from Trigger I checked the OAL of my reloads and even though they are below maximum, this rifle does indeed have a short throat so I seated the bullets deeper to match the factory rounds I was shooting. It worked out great. These loads are now shooting fine. The bullets weren't seated out touching the lands but apparently they were close enough that the pressure greatly increased.

Out of all of my years of handloading, I didn't realize that bullet seating could have that much impact on pressure but then again, I have only shot factory rifles and military rifles and not custom rifles like the one I just purchased.

So just a heads up to all out there, when buying a used custom rifle you may need to be extra careful with your handloads as the rifle chamber may be tight or it may have a short throat.

According to quickload, seating the bullets in the lands can cause an 8000 psi increase in pressure.

quote:

Originally posted by Upnorthguy:
Well, after reading the post from Trigger I checked the OAL of my reloads and even though they are below maximum, this rifle does indeed have a short throat so I seated the bullets deeper to match the factory rounds I was shooting. It worked out great. These loads are now shooting fine. The bullets weren't seated out touching the lands but apparently they were close enough that the pressure greatly increased.

Out of all of my years of handloading, I didn't realize that bullet seating could have that much impact on pressure but then again, I have only shot factory rifles and military rifles and not custom rifles like the one I just purchased.

So just a heads up to all out there, when buying a used custom rifle you may need to be extra careful with your handloads as the rifle chamber may be tight or it may have a short throat.

Thanks for the follow up !! roger