I loaded some 130gr Hornady Interbonds for my Rem 700 Titanium in .270. My manual says COL should be 3.280 but I had to get them down to 3.210 before they would chamber and lock up. I can take a factory 130gr corelokt round which is longer and it chambers just fine. Have I screwed something up here or is it a difference in bullets? Is it safe to have the bullet pushed into the brass further? Thanks in advance.

I suspect it has to do with the ogive of the bullet. Without being able to see the difference in the loaded rounds, it is difficult to give you a definitive answer, but that is probably the issue.
And as long as you have not gone above the max load for the bullet selected, seating a bullet deeper is not an issue. Most slow-burning powders shoot better slightly compressed. There ARE some folks that advise not to seat boattails so deeply they protrude into the body of the case, but I have never had a problem when I did it...

so are you saying that they were contacting the rifling lands which would not allow the bolt to rotate into battery? were there scars on the bullet?

If so, the ogive is further foreward than on the factory loads and will need to be seated deeper. If there were no scars on the bullets at the original COL, then that is not the issue.

Have you tried to measure the distace to the lands with that particular bullet? Just wondering if you are really hitting the lands with the bullet or if there might be another problem...??? I would expect the interlock to have a more aggressive ogive than a corelokt, and therefore be seated longer to get to the lands...but I don't have them to compare side by side.

Thanks Guys,
The bullet was hitting the lands, that's why I kept shortening it. I was worried about too much pressure building by seating the bullet deeper. Keep the advice coming because this is all new to me. Thanks again.

.05" wont make any difference at all. In fact it may lower pressure. Loads where the bullet touches the lands can create a higher pressure. As you back the bullet off the lands pressure should drop a tiny bit. As you continue to go back into the case the pressure will rise due to lower case volume. All of these changes are very small, and probably wont show any noticeable effect on a given load. Just watch for signs of excessive pressure as you work your load up.

270is one of those "rare" factory cartridges where the "rather blunt" factory bullet is actually sleeker than it looks and "hangs out" further than you would expect. Then when you pick up that neat plastic tip bullet you would absolutely "assume" you will be able to hang it out even further.
Put another reloading tool on your wish list. Either a kit from stoney point or the 6 caliber "nut" from sinclair so you can measure your distance to lands with different bullets.
I have the sinclair and think it's a good value for the $$$. Once you know that a bullet bottoms out at a certain measurement you will know where to stop with any bullet of different profiles. When I find a load that shoots good the first place I start with a new bullet is the same "jump to the lands" as the one that shot good and often this works out good for accuracy with the new bullet.

30-06 is another caliber where they say you should be able to set bullet length to 3.300" but often you can't because bullet profile stops you short of that.

Re: worries about pressure it should have an extremely minute change and be nothing to worry about at all.

It's virtually impossible to push a bullet "into" the rifling more than a few tenths unless the bullet is glued or soldered into the case. Try it and you'll see. Loading a bullet long and letting the rifling do the final seating is a standard loading practice among bench rest shooters and is perfectly safe. The only danger is if you have to unload a round without firing it because the bullet may be pulled from the case, spilling powder in the action. Creating dangerous pressures by seating a bullet to touch or jam is an old wives tale. After all, we're only talking about differences of thousandths of an inch, not fractions of an inch such as Weatherby freebore. The difference in pressure between two cartridges is probably greater than any you would create by seating depth. If you reach the point where seating depth is that critical you are probably over-loading that cartridge to begin with. JMHO. Other opinions may vary.

Ray

FWIW, several posters have shown graphs from strain gauge pressure measurement systems of identical loads...except for seating depth. There is a definate raise in pressure when the bullet is seated into the lands, as opposed to just shorter. IIRC it was on the order of 1-2k PSI, so you are right, it is not a concern unless one is already at the ragged edge of safety.

The mechanism is not so much about case capacity, but about the force required to start the bullet moving. Seating well into the rifling makes pressure rise more before the bullet starts to move, where if the bullet can move after just being released from the case, its momentum carries it through the entry to the rifling much easier.

Personally, I list it in the 'something to be aware of' category, not the 'something to worry about' category.

YMMV!

Either you have a really really short chamber, or I have a really long one. My loads for my Rem 700 .270 are 3.335, and I'm not even close to the lands. I do plan on getting a sinclair tool so I can see just how far off I am. I just thought it was a little weird how these two similar rifles have such a huge difference in chamber length.

Steel Slinger,
I was hoping to hear from another Rem 700 owner. The barrel on the Titanium is only 20" so I don't know if that makes a difference or not. But it is strange they are that much different.

Slinger

No need for a Sinclair tool to see how far off the lands you are. Take a bullet and drop it into the chamber, point first. Take an ordinary lead pencil and with the eraser end hold the bullet lightly against the lands. Then push a flat ended cleaning rod gently down the bore until you make contact with the bullet. Now, with your third hand make a mark on the rod even with the muzzle. Remove the rod, pencil and bullet. Now take that exact same bullet and load it into a dummy case (no primer or powder) exactly the way you do your ammo. Chamber it and close the bolt. Put the rod back down the bore until it makes contact with bullet and make another mark even with muzzle. The difference between the two marks is how much you are off the lands. You have to use the same bullet for both operations, the rod has to have a flat end, and make double damn sure the round is a dummy!

Ray

Ray

quote:

Creating dangerous pressures by seating a bullet to touch or jam is an old wives tale. After all, we're only talking about differences of thousandths of an inch, not fractions of an inch such as Weatherby freebore. The difference in pressure between two cartridges is probably greater than any you would create by seating depth. If you reach the point where seating depth is that critical you are probably over-loading that cartridge to begin with. JMHO. Other opinions may vary.

Cheechako, let me tell you about my experience with a 308 Norma Magnum: I thought exactly like you did, and proceeded to take a 308 Norma case, using load data from the Accurate Manual #2, and load a 180-grain projectile (actually, I loaded ten of them). I seated them out to ~.005" off the lands, thinking that the blurb in the Hornady manual was a good idea, based on prior experience. And I headed to the range with a rifle that had previously headspaced at .003". Well, long story short, the second round blew the primer out of the pocket. I was flabbergasted, because I was about a grain below max.

Then I read Ken Waters' account of his pet loads for said cartridge, and he notes that Norma specified 6MM of freebore for the .308 Norma when they designed the round. 6MM is almost a quarter of an inch!!!!!
So, I go back and seat the bullets to his recommended overall length, and all pressure signs disappear. The rifle becomes a <MOA firearm.

I guess what I am saying is to read all you can, and absorb all you can before loading for a new chambering... This was a new occurrence to me, but definitely an eye opener.

Doubless

All I can say is that you were not a full grain below max if you blew a primer with bullets seated off the lands. Max in your rifle was obviously much more than one grain below the book. Seating the bullet back 1/4 inch is obviously going to reduce the pressure but it is also going to reduce velocity and accuracy. Anyone loading the Weatherby cartridges is familiar with how that works. Loading manuals will tell you that if you're using a Weatherby cartridge in a barrel with a conventional throat you have to reduce your charges accordingly, usually about 10%. I have never seen such a warning with the Norma calibers but if it happened to you there must be something to it. Your rifle obviously had a conventional throat rather than a freebore.

I will stand by my previous post that seating to touch or jam versus seating a few thousandths off is not going to cause pressures to skyrocket beyond the strength of the brass unless your load is on the verge of popping primers to begin with. I agree with CDH. Seating depth is something you have to be aware of but it certainly is not something to fear unless you operate right at the ragged edge to begin with. When I reach that point I simply go to a bigger cartridge.

Ray

I'll use the method that Cheechako described and get back to you when I find out what my absolute max col is for my rifle.

quote:

Originally posted by Steel Slinger:
Either you have a really really short chamber, or I have a really long one. My loads for my Rem 700 .270 are 3.335, and I'm not even close to the lands. I do plan on getting a sinclair tool so I can see just how far off I am. I just thought it was a little weird how these two similar rifles have such a huge difference in chamber length.

I'll second SSs 270 OAL.

My 270 reloads for a Rem M700 are out to 3.40" and I'm not on the lands either!

Ok, here's my measurements.

COL (dummy round) is 3.335.
Difference between that and just a bullet held in with a pencil is .09.
So, my max COL (seated into the lands) is roughly 3.425 inches.

I don't think that if I made my rounds that long they would fit in the magazine. I think I will adjust my dies out just a couple hundredths more since barnes recommends to be .05 off the lands for the TSX and I'm .09 as is.

Amazing how two similar rifles can have such different measurements. The problem you had was probably, as mentioned above, caused by the different bullet's lengths from ogive to tip. I would think that you can seat it deeper without any problems as long as you don't compress your load. JMO.
Good Luck

quote:

All I can say is that you were not a full grain below max if you blew a primer with bullets seated off the lands. Max in your rifle was obviously much more than one grain below the book. Seating the bullet back 1/4 inch is obviously going to reduce the pressure but it is also going to reduce velocity and accuracy. Anyone loading the Weatherby cartridges is familiar with how that works. Loading manuals will tell you that if you're using a Weatherby cartridge in a barrel with a conventional throat you have to reduce your charges accordingly, usually about 10%. I have never seen such a warning with the Norma calibers but if it happened to you there must be something to it. Your rifle obviously had a conventional throat rather than a freebore.

I don't like being accused of lying. I have handloaded for 20+ years, and I CAN read a scale... Just went and pulled the load data, and I misspoke earlier. The load was 68 grains of AA3100 behind a 180. Top load for the 180 was 72.5 grains. So I was WAY below max. And again, all I did to "fix" the problem was seat the bullets 1/4" deeper.

And secondly, the way that Weatherby gets the velocities they do is by jump-starting the bullet. Hence the freebore. They are WAY overbore, and use far too much powder. So they push the bullet back and STILL generate too much pressure for velocity gained, IMO.

Believe what you will. Go ahead. Take a friend's Weatherby caliber, push the bullets up to the leade and touch off a round loaded to book max. See what you get.

I am done.

doubless

I certainly didn't mean to accuse you of lying and if I came across that way, I apologise. What I was trying to say was that when a particular load in a particular rifle pops primers it means the load is too hot for that rifle. Regardless of what any loading manual will say you have to go by actual results.

Regarding Weatherbys - many long range shooters use Weatherby cartridges in custom barrels that have been chambered without the typical WBY freebore. They are able to obtain the same velocities simply by starting low and working up while shooting across a chronograph and watching for pressure signs. IMHO the WBY freebore is nothing more than a gimmick to CYA loads that would otherwise be over-pressure. For any given capacity case there is a maximum velocity that can be obtained within reasonable pressure limits. There's more than one way to get there. WBY uses one way but long range shooters who are after supreme accuracy prefer to do it another way.

Again, I'm sorry for any misunderstandings.

Ray

quote:

Regarding Weatherbys - many long range shooters use Weatherby cartridges in custom barrels that have been chambered without the typical WBY freebore. They are able to obtain the same velocities simply by starting low and working up while shooting across a chronograph and watching for pressure signs. IMHO the WBY freebore is nothing more than a gimmick to CYA loads that would otherwise be over-pressure. For any given capacity case there is a maximum velocity that can be obtained within reasonable pressure limits. There's more than one way to get there. WBY uses one way but long range shooters who are after supreme accuracy prefer to do it another way.

I understand, and agree wholeheartedly. Apology accepted, no hard feelings. It just surprised me when I had the primer blow out, and looking back found I was middle of the load chart, 4.5 grains under the AA max. THAT curled my hair (what's left of it...).
And when I pushed the projectiles back down, the way Ken Waters recommended, the problem disappeared; the cases are gorgeous with no pressure signs, pockets are tight, etc.

Haven't shot the rifle in several months now, too darned hot. But intention is to continue up the scale with powder charge and see what happens. I figure the Nosler recommendation of miking just forward of the case web is the best way to go: Stop @ unfired diameter +.0005"...

I just wanted to say thanks to all of you that responded. I picked up some great info and ideas. I did figure out the problem. I didn't have the sizing die adjusted properly and it was not quite sizing the brass all the way down the neck and it was leaving a tiny bump at the base of the neck. It was really hard to see but I could feel it with my fingertip. I readjusted the die and the the c.o.l. is now at 3.395 just off the lands. I went out this morning and shot different loads and got all of my groups except for two under an inch. It looks like 59 grains of H4831 is going to be the best so far with a .72 group. Thanks again for all of your help.