Bullet "slam" in magazine - tips deforming

I'm looking for a little help or advice from bolt action big-bore shooters on how to prevent a problem with rounds in the magazine. Here's the issue:

I just started the barrel break-in on a Ruger 77RSM in .416 Rigby. I loaded up rounds with 400gn Barnes TSX pushed by 100gn of RL22. This is 3gn under max load and averages 2332 fps through the chronograph.

I thought that I should check for bullet movement (crimp tightness), so each time I fired the rifle, I put 2 rounds in the magazine. There is about 1/8" clearance in front of the bullet tip.

I'm finding that the tips of the TSX bullets in the magazine are getting badly deformed after only 2 shots. The tips are hitting the front side of the magazine.

Are there any tricks for preventing this?

I thought about a thin plastic insert glued to the front of the magazine to cushion the bullet tips and might test this over the weekend.

Thanks for your help.

- browningbbr

I used to shoot nosler partitions in my .300 WBY and noticed the same thing. If it's any consolation, it actually seemed to make very little difference when it came to down-range accuracy. All the same, the effect bugs me too. Bullets are just "supposed" to look a certain way.

I switched to the polymer-tipped TSX in that gun. I'm currently loading Barnes TSX for my .416 Rigby and if the gun ever gets back from CZ, I'll be watching for exactly what you're describing. I must admit that I'm surprised you're noticing deformation with that bullet. It's an all-copper tip, not soft lead.

I'm hoping that Barnes will eventually broaden their TTSX line to include the .416 bullets. Once that happens, the problem will be solved.

Are you getting any bullet movement in the neck or is the crimp doing its job?

BryceM

I am getting some bullet movement, but not a lot.

I set the crimp on the first few rounds so that the case rim just made contact with the bullet shank in the annular ring.

I've increased the crimp a bit (about 1/6th turn of the die) for the next 5 rounds and will test it over the weekend if the weather cooperates.

- browningbbr

Bullet deformation has no effect on trajectory or terminal action on game, at least from a hunting standpoint...so its not a big deal.

One can have a sliver of steel soldered in the magazine box located at the junction of the shoulder and neck. this prevents forward movement caused by the recoil but Its just another expense...

You can seat your bullet back and use a good crimp so that you dont' get them pushed back into the case as that is a real problem and one that should be addressed...this will solve the problem or at least help..other than that I wouldn't even worry about it.

Also the use of Round Nose bullets and simi pointed bullets but to a lesser degree pretty much solves the problem..

Thanks Ray, that gives me more options to consider.

- browningbbr

... I agree with Ray! For all my years of shooting I've seen no down Range results indicating that it hurts accuracy. My suggestion is once you find out the rounds aren't moving forward or backward in the magazine & accuracy is ok is don't load up the magazine while shooting at the range! One case at a time helps cool the gun between shots and it will take a little longer for the next shot! i have the same problem with my 375 & it's just a fact of life for me!

Yeah - I deliberately put rounds in the magazine to find out if my crimp was sufficient. I'll keep gradually increasing crimp until I get them to stay put.

I like Ray's suggestion of soldering a piece to the magazine at the shoulder-neck junction (datum point) to stop movement. I'll probably buy a spare mag liner and magazine follower so I can experiment a bit.

- browningbbr

You will need one on both sides..The used to make such a gizmo, but I guess it didn't sell or whatever..it worked really well..I had one but don't know what ever happened to it..it just slide down in the magazine and spring tension held it as I recall..

On a similar subject I saw something not long ago that is very unusual. The rifle was a .458 that belonged to my PH. When he tried to chamber a round it would not go in. The ammunition was some kind of local South African brand, I cant remember the name. But it seems this round had been in the magazine so long that it had actually belled the case mouth at the crimp. The round was a solid so there was no nose flattening. This could have been potentially a problem since it was a back up rifle. It pays to run them threw the chamber even factory rounds every once in a while. Especially if the rifle is used for back up work.

Hey browningbbr,
Woodleigh make a range of Protected Point bullets and they have a 400gr bullet for the .416 available. Premium product, excellent terminal performance and no deformed bullets! You don't have to work around the problem with this bullet as it doesn't exist.
I have used a Woodleigh bullet on 40 odd animals in Africa and a lot of animals at home with excellent results.

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Originally Posted by Double D

It pays to run them threw the chamber even factory rounds every once in a while. Especially if the rifle is used for back up work.

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I agree 100% with Double D. Everyday, I usually chamber a bullet into and out of my gun, just to make sure there is nothing wrong. I check the safety to see it works properly and I try to make sure the gun can eject and chamber another shell. Believe it or not I've found plenty of problems. The same thing with the scope: I check the optical picture, make sure it's in focus, lenses are clean and the scope mounts are secure. There's usually time in the field to do this.

schembridan,

Thanks. I'll take a look at the Woodleigh bullets.

I've isolated the problem to the top bullet in the magazine. The tip of that round hits the edge of the infeed ramp when the bolt is holding it down. When the bolt is drawn back, spring tension in the magazine causes the tip to raise a bit, making the cause less visible.

Slightly more crimp tension solved the issue of bullet "creep" associated with recoil.

Enysse hits on an important point: Checking all rifle components and function prior to hunting each day. I've always done this. I just figured that I was being anal about finding problems that could ruin a hunt. 'Guess I'm not alone.

- browningbbr