I have a custom rifle with a Bauska barrel I think. It shoots Hornady original 139 gr. bullets very well. It shot 175 gr. Nosler partitions very well. Since restocking in fine wood, strange things have happened. The load 175gr Partition and 46gr N160 with 210M primer has started popping primers. This was a worked up load and has been to Africa several times as a backup rifle. The Hornady bullets are flying at about 2975 f/s. and are accurate. I dont like to hunt with Hornady bullets. I cannt get anything else to shoot well in my rifle. I checked the twist rate and as far as I can tell it is less tha 1;10 but not 1:9.5. Wierd. Have you any hints..???

You have excessive pressure for primers to bulge , why are you using mag primers ? my books are all below your loads for this caliber ! The max for N160 is 45.9 and large rifle primers Not Mag primers !

concho, the 210M is a match primer. I agree though, I don't use mag. primers in samll cases like the 7x57.
lb404, have you changed anything else in the load; new lot of powder, new lot of primers, bullets? Restocking should have no affect on the pressure of the load. Sometimes a lot change will affect a load especially if you are running near the high end. Just back off your load 1/2gr & see if it calms down. FWIW, I find the BR2 roimer a bit milder than the 210M.

Put the old stock back on! roger

It may not necessarily be your bullets. I've got three 7x57's, (Ruger #1 light sporter, Ruger #1 International and a Whitworth bolt) They all perform well with a variety of bullets with IMR 4350. I don't however, go up to 175grs. My favorite is the 160gr Speer Mag Tip.

Thanks for your responses all. This is really frusterating as I have not been able to get any kind of good repeatability out of this barrel. I am tempted to lap the hell out of it with JB bore cleaner and see if smoothing it out will change things. I havve tried everything from RL 22 down and not much success. In the restocking there might be some tight areas. I will see if I can get it worked out. This is too fine of a rifle to let go. Any other laod suggestions? I have made up some H414 loads to try this weekend . I guess we will see!

My 7X57 likes H 414 with lighter bullets and RL-19 with heavier pills, Ive not tried 175 grain bullets from my rifle, 2975 is prety fast for a 7X57, I think back off a grain or two. of you need that much velocity, get another cartridge a .280 will fly that fast...tj3006

quote:

Originally posted by lb404:
Thanks for your responses all. This is really frusterating as I have not been able to get any kind of good repeatability out of this barrel. I am tempted to lap the hell out of it with JB bore cleaner and see if smoothing it out will change things. I havve tried everything from RL 22 down and not much success. In the restocking there might be some tight areas. I will see if I can get it worked out. This is too fine of a rifle to let go. Any other laod suggestions? I have made up some H414 loads to try this weekend . I guess we will see!

I'm just a little confused ;if the rifle shot the 175gr. bullets just fine before you restocked it why are you looking to make a correction by working on the barrel.Those tight areas you mentioned should be getting the lion's share of your attention.JMHO. roger

I agree about the stock needing attention, my stock guy is out of town now so that will have to wait. I noticed when shooting then cleaning the rifle that the bore fouls quicker and feels less slick when I clean it.I thought that lapping it a bit might smooth out the rough areas and reduce the fouling and might help accuracy.

quote:

Originally posted by lb404:
...Since restocking in fine wood, strange things have happened. ... Have you any hints..???

Spray the wood with Chlordane. Probably Termites exerting HIGH Pressure on the sides of the Barrel.
---

Probably something has changed in your Cartridge Components from Lot-to-Lot - different Case Capacity, Primers hotter, bullet Profile, or the Lot of Powder is hotter than the previous Lot. I normally use SAFE MAX Loads and when something changes in the Components, it can just as easily Increase the Pressure as Reduce it.

If the ambient temperature is higher than when you Developed the Loads and you are near SAFE MAX, that can be enough to do it too.

Or perhaps there is fouling present in the Bore that just can't be seen. Try a tight "Paper Patch" on a Jag and see if you can "feel" a rough spot near the throat. If so, the JB Compound might just clean it out. It does for me.

By the way, I agree with Thomas Jones about H414 being an excellent Powder for the 7x57mm as well as the 7mm-08.

What I would consider doing is put the rifle back in the original stock and see if the load still gives trouble. If so, then that could eliminate the problem with the new stock.
However, I'm thinking the loads are on the ragged edge of being a bit too high in the first place, especially if you have a new lot of the same powder.
I have three rifles in 7x57 and all of them thrive on W-760 powder. W-760 is said to be the same as H-414, just different lots of the same powder so the suggestion of H-414 is spot on.
Frankly, I do not see the need for a 175 gr. Nosler Partition in a cartridge like the 7x57 as you really can't push it fast enough to really need a bullet that tough. However, as the late Elmer Keith once said, "A man can scratch his own fleas in any manner that he chooses." or something to that effect.
I'm thinking the problem is in the load as the 139 gr. load still seems to shoot well. Most likely to me is a change in the powder lot is the culprit, but who knows for sure?
Paul B.

The "wonder bullet" in my 7x57s appears to be the 160 grain Nosler Accubond, at least as far as accuracy is concerned. I have four 7x57mms, and all shoot the 160 into an inch, except for the fourth rifle, a Winchester M-70,which prefers lightweight bullets. I'd say that the problem is in your stock if the barrel shot well in the past. Work on your bedding some more.

LLS

I agree with the suggestion that the stock my be the primary issue, however the Hornady bullets print with the same level of accuracy as they did in the fiberglass stock. I have been trying to work on the load based upon, as you all say, the components are different now. I am having a similar problem with my 6.5 Remington Magnum in that none of the new lots of RL 22 will come close to the velocity or accuracy that the original loadings developed. I am fortunate that I have about 50 more rounds of the original loading and that is enough for me for quite a while. I have some 140gr. and 160gr. Accubonds to try this weekend in the 7x57.

quote:

Originally posted by lb404:
...none of the new lots of RL 22 will come close to the velocity or accuracy that the original loadings developed. ...

A lot of folks have excellent luck with the "RL Powders", but that just hasn't been true for me at all.

Get up near a SAFE MAX and I've noticed sporadic Pressure Fluctuations. Noticed it in about 4 different RL Burn Rates. And I tried 3-4 pounds of each one of those Series.

Gave what I had left to a buddy who also didn't like it. He gave some of it on to another guy who just uses it for Fire Forming Loads and the rest was scattered over his garden.

I think I may have the answewr to your primer issue, I bet you primer pockets are streaching. Try seating a new primer and see how it seats. If it goes in with less resistance than it used too, you have you answer.
Again that would be a simple remady, back a grain or 2 off your charge. The 7x57 is a hell of a cartridge. But throating and seating depth of your bullet has alot to do with safe or unsafe loads. If you Drop your charge weight by
say 2 grains your load should still be at leas 2800. What deer can't you kill with that , and how far do you plan to shoot !
...tj3006

Thanks for your suggestions, I will shoot it this weekend and let you know.

quote:

Originally posted by concho:
You have excessive pressure for primers to bulge , why are you using mag primers ? my books are all below your loads for this caliber ! The max for N160 is 45.9 and large rifle primers Not Mag primers!

"What may be a maximum load in one rifle may be quite mild in another, and vice versa!" Bob Hagel

I cannot believe that merely restocking a rifle would cause what was an acceptable load that was worked up correctly in a specific rifle, to all of a sudden be over maximum in that barrel! Are you suggesting that "pressure" from a piece of wood on the outside of a barrel can affect internal ballistics? That would indeed be a new concept! For me, anyway!

There's something else going on here!

Were ANY of the componenets (case make, batch, primer type/lot number, propellant type/lot number, etc.) changed between the time you worked up the load and the bad things started happening?

7x57 update.
I am still having some trouble with the rifle. It is still not as accurate as it was with original loadings. These were done about 7 years ago so none of my current components are quite the same. as a result, I took 50 new cases and completely detailed them, full length sizing, trimmed all to the same length, uniformed the primer pockets, and deburred the flash holes. This opperation was done on the original cases also. I then loaded up some cases using the loads that were developed 7 years ago. The range tests are disappointing at best. 1.5" is about the average it will do. I have again thoroughlt cleaned the barrel. I used my bore scope to look at the bore-all OK there. I guess I need to just start over on load development. All screws are tight on action and scope and mounts, and all looks OK. I did a twist rate test and to the best of my ability the twist is between 1:9.5 and 1:10.0.

I have not changed primers. I might change primers to CCI 210. You know that this is a real pain in the butt.

One other thing to think about ... cartridge cases. Are the cases you use now from the same lot you were getting such good results from originally. If the inside demensions changed just a tad, it could throw your load into a tailspin if you were at the top-end of the load in the first place. When developing loads and I find a good one, I make sure that I get a good water capacity of the case in weight and then I make sure I keep an average weight of the cases (say the weight of 10 cases divided by 10). I also make sure that I chronographed the load. That way, if the volumn of the case changed from lot to lot I can adjust accordingly, but I make sure that I adjust the load up to, or down to, the velocity that shot so well in the beginning. So far, 10 times out of 10 when I use velocity as the deciding factor, the loads remain accurate. Hope this may give you some more food for thought. Tom Purdom

I had a thought (admittedly a dangerous thing) that may help. It regards the bedding. It may not explain the pressure issue, but it may assist in accuracy.

Perhaps either the new or old stock bedded the action differently. "Normally" ( a subjective term) you want to have an action bedded so there is no action flexing, as the front or rear action bolt is tightened.

You can test by having an unloaded gun standing vertical, butt plate down on a table (holding the rifle in your hands. Place your finger near the tang (rear action bolt) and the stock interface. Loosen the rear action bolt with your finger on the tang/stock interface. Do you feel or see the tang move away (unflex) as you loosen the rear action bolt? If so, then your stock (bedding) may be putting a variable force on the barreled action, and may be causing accuracy issues.

Tighten the rear action bolt again, and see/feel if the tang moves again toward the wood as it is tightened. If so, then you may need to either rebed the action, or just put a dab of epoxy/bedding compound of choice under the tang (only tighten the front action bolt, not the rear-until the epoxy sets,)

If the action springs or flexes "too much", and the loosened rear action bolt causes the barrel to be in a "weird" position in the barrel channel of the stock, then you will likely have to remove some wood from the front portion of the action to get the barrel to be in proper position in the stock barrel channel (centered and level). Then it may be best to skim coat the entire action.

Again, it doesn't explain the pressure issues, just possible accuracy cause/effect.

Perhaps the new barrel is throated differently, so the bullet seating depth needs to be reexamined. You can take a fired case and pinch the neck with your fingers to make it slightly oblong (to apply enough tension to gentle hold a bullet, no powder or primer). Set the bullet of interest in the case, with essentially the longest overall bullet length possible (bullet only seated in ~ 1/2 way down the neck). Gently place the EMPTY case/bullet in the action (or remove the bolt and slide case head in the bolt's extractor, and replace bolt with dummy cartridge back in action). Slowly close the action, and then gently remove the dummy cartridge. You want to ram the lighlty tensioned bullet into the lands to see what the overall lenth is of that particular bullet, compared to your old overall length from your old barrel.

Maybe you were 0.020" off the lands before, and are now 0.010" INTO the lands (or something like that). Seat your bullets a little deeper in the case (0.010" increase in seating depth(shorter overall length) or so for each 3 shot group, and observe pressure signs and accuracy (keep powder dosage the same). Backing off the overall length will likely reduce pressure.

Good luck

The pressure issue is in my mind, explainable. I do load to the top of the curve on pressure. If there were a change in any component that might cause a pressure spike. This is not a new barrel, it is the same barrel I started with.

The accuracy issue is problematic. I need to have it bedded again and the barrel channel opened up a bit and see if that will give some relief.

I'm new to this forum and to the 7x57, but I do live in OK, and if you've been shooting recently the ambient temp. may be affecting pressure. We've had about a month of 100*+ weather. I agree that bedding in the new stock could be an issue, but I think the heat is too.

In a closely related matter, last weekend (in Tulsa) I bought a sporterized FN Mauser in 7x57. When I got it home, I discovered that the cases fired in my Ruger RSI (now traded) would not fit in the mauser's chamber and had to be carefully resized. The guy I bought it from gave me what was left of a box of PMC 175gr cartridges, and I noticed that the primers of the 18 rounds he fired had pushed out of the primer pockets, though the carts. fit the chamber and the bolt closes on them. I suspect a tight chamber and bore (which I'm going to slug) -- but the seller said he had zeroed the rifle at 100yds. He had obviously been shooting in the Oklahoma heat too. Could this be a cause of pressure signs, given that you load at the top of the pressure curve?

Richard

Accuracy problems in a 7 x 57.. try a load of 40 grains of IMR 3031 with ANY grain bullet ya want.. 175s are safe, and so is anything on down..

This has tightened up accuracy on my two Ruger 7mm Mausers... and I have had others on line here, that have tried it and also had the same results...

But if the addition of the new stock has changed something.. it is either the heat and humidity or the new stock is putting pressure somewhere on something...

Good luck tho...

cheers
seafire

quote:

Originally posted by RichardinOK:
I'm new to this forum and to the 7x57, but I do live in OK, and if you've been shooting recently the ambient temp. may be affecting pressure. We've had about a month of 100*+ weather. I agree that bedding in the new stock could be an issue, but I think the heat is too.

In a closely related matter, last weekend (in Tulsa) I bought a sporterized FN Mauser in 7x57. When I got it home, I discovered that the cases fired in my Ruger RSI (now traded) would not fit in the mauser's chamber and had to be carefully resized. The guy I bought it from gave me what was left of a box of PMC 175gr cartridges, and I noticed that the primers of the 18 rounds he fired had pushed out of the primer pockets, though the carts. fit the chamber and the bolt closes on them. I suspect a tight chamber and bore (which I'm going to slug) -- but the seller said he had zeroed the rifle at 100yds. He had obviously been shooting in the Oklahoma heat too. Could this be a cause of pressure signs, given that you load at the top of the pressure curve?

Richard

Richard. If I understand your post correctly, the 18 rounds that were fired in the rifle had the primers protruding from the cases? I'm thinking you'd best take that gun to a good gunsmith and have the headspacing checked. While it could be that PMC ammo's shoulder might be a bit on the short side, I'd still get that headspacing checked. Better safe than sorry.
Paul B.

Paul B. Thanks for your post. I talked with my gunsmith this morning and we agreed not to fire the rifle until he sets the barrel back and re-cuts the chamber. I still think ambient temps can cause excess pressure, but this one is definitely a headspace problem.

Thanks again, Richard

I think that when you initially fire a round, the primer does back out a bit. The firing pin pushes the case forward until the shoulder, or belt or rim, stops the case then the primer is dented. Next when pressure starts to build, the case expands and moves back against the bolt re-setting the primer. Except in crimped in cases that is. Were the problem excessive headspace, I think a bright ring would show just in front of the case head where excessive streaching would be occuring and the case preparing to fail.

What I really don't get here is how restocking a rifle creates excessive headspace? Did I miss something somewhere????

quote:

Originally posted by Don Fischer:
I think that when you initially fire a round, the primer does back out a bit. The firing pin pushes the case forward until the shoulder, or belt or rim, stops the case then the primer is dented. Next when pressure starts to build, the case expands and moves back against the bolt re-setting the primer. Except in crimped in cases that is. Were the problem excessive headspace, I think a bright ring would show just in front of the case head where excessive streaching would be occuring and the case preparing to fail.

What I really don't get here is how restocking a rifle creates excessive headspace? Did I miss something somewhere????

Not necessarily so. Currently, I have a milsurp Steyr Mauser I bought that was rebarreled to 7.62 NATO. It too has a headspace problem and yes, the primers protrude in a similar manner as Richards problem. As I plan for it to be a donor action, it's no big deal in my case.

No, the restocking was not the cause of the headspacing problem in his rifle. I just happened to pick that problem up because of the remark about the protruding primers which did suggest that the rifle had other problems beside the accuracy situation.
Paul B.