Crimping 375 H&H

[Heym SR20]

I do the same for the first round. Once that first round is made and measured to be dimensionally correct, I re-insert it into press and adjust seater stem down to rest on completed cartridge and lock that off. Thereafter, all same-length cases can be seated and crimped in one pass rather than two.

That "same-length" caveat is important. I have found quite a variation in once-fired case lengths. View attachment 165770 View attachment 165771 View attachment 165772 If I don't trim cases to same length, I have to be committed to per-case crimp+seat faff.

With 7x65R I always crimp as I find it improves accuracy. Must admitI tend to do in two passes. First with the RCBS seater die back off a touch but the stem correct for bullet seating depth. Then once all bullets seated, back stem off, wind in the seater die till it touches case mouth, then wind in another 1/3 of a turn and run them all through again. I like to positive pressure onto the bullet, and find accuracy improves. Also means bullets do not move.

I have seen on about four occasions on hunting rifles where reloaded an uncrimped ammo bullets have moved in the case. First time I was using an estate rifle. We had got into a load of hinds, but they spooked so unloaded. Bullet stayed in the lands powder everywhere. It was an embuggerance factor, but the rifle was useless until we got the bullet out - which required a cleaning rod, two hours walk away down at the lodge. Have the same happen on dangerous game would have been a big embuggerence.

What had happened here is that they had two rifles of the same calibre and the stalker had n't changed the settings on the dies when he reloaded a batch of rounds for this rifle. The bullet was a touch long - hence gripping the lands.

My view - for a hunting rifle - full length size and crimp. Agreed might not the last fraction of an MOA in accuracy, but I want it reliable.

 

[Namman]

PH has said he is happy with handloads and that there should be no problems importing them into SA
The above story with the 416 implies the reason for the problems was they had not chronographed their loads and potentially did not make adequate first shots. Surely if the velocity is adequate at Uk temperatures then the pressure and therefore velocity will increase in warmer climes. The other thing is That the majority of wounded animals are down to shooter error rather than ammo failure!
If you look back in history there are occasions where factory ammunition has fallen short of published velocity and caused problems (eg 458 win mag) so I’m not sure that buying factory ammo makes anyone immune from issues like that but proper preparation should reduce the chances of issues occurring

you are correct they listened to someone who is a respected gunsmith and he told them to reduce their loads to compensate for the increase in temperature in Africa. When they got back they did chronograph them and found they were several hundred fps lower than expected. As you say it is madness not to chronograph dangerous game loads.

 

[Namman]

With 7x65R I always crimp as I find it improves accuracy. Must admitI tend to do in two passes. First with the RCBS seater die back off a touch but the stem correct for bullet seating depth. Then once all bullets seated, back stem off, wind in the seater die till it touches case mouth, then wind in another 1/3 of a turn and run them all through again. I like to positive pressure onto the bullet, and find accuracy improves. Also means bullets do not move.

I have seen on about four occasions on hunting rifles where reloaded an uncrimped ammo bullets have moved in the case. First time I was using an estate rifle. We had got into a load of hinds, but they spooked so unloaded. Bullet stayed in the lands powder everywhere. It was an embuggerance factor, but the rifle was useless until we got the bullet out - which required a cleaning rod, two hours walk away down at the lodge. Have the same happen on dangerous game would have been a big embuggerence.

What had happened here is that they had two rifles of the same calibre and the stalker had n't changed the settings on the dies when he reloaded a batch of rounds for this rifle. The bullet was a touch long - hence gripping the lands.

My view - for a hunting rifle - full length size and crimp. Agreed might not the last fraction of an MOA in accuracy, but I want it reliable.

That observation is to do with col not crimping . If bullets move that easily I would be concerned about neck tension.

 

[Namman]

That observation is to do with col not crimping . If bullets move that easily I would be concerned about neck tension.

you must have very loose bullets in your cases with the above post and your previous post.
Some years ago I was loading .300 win mag with Hornady 220gr round nose bullets using Lee dies. I noticed that you could twist the bullets in the loaded rounds. It turned out to be an oversize expander ball and slightly undersize bullets.

 

[reiver]

Just my thoughts . If your going to spend the time and money traveling
To the middle of no-wear to shoot something that is liable to be very angry if it goes wrong!!! I Would be crimping my ammo weather or not I thought it needed to? It only needs to happen once that a bullet moves
And you get stomped on for the sake of a crimp! !!
By the way I crimp all my ammo from 30 cal up just because it is one less problem.

 

[Hanechdene]

I crimp the .375 bullets that have a cannelure which for me are GMX and DGS/DGX bullets however I do not for Sierra ones.

Looking at the OP’s picture I would have thought the bullet needs seating a tad deeper so the roll crimp from the die is engaged with the cannelure.

Personally I set the die up to seat and crimp in one operation and not two.

I have a discipline when refilling a magazine of putting the new round at the bottom and not the top.

 

[Alistair]

I crimp my .375, no matter what bullet I'm using.

There doesn't really seem to be any downside in doing so. It doesn't hurt accuracy, it barely adds any time to the loading process and it gives a bit of peace of mind. It might even have some practical use.

Lee FCD is the best tool for the job. Personally I take the approach of plenty of crimp on this calibre. Certainly the bottom bullet in the mag looks a little battered after a couple rounds, but they don't seem to move and still load/fire/hit as you'd expect them to.

Contrary to one comment above, the 375 is good fun to plink with, but only really in field positions. Off hand I regularly shoot 20 rounds through mine in a session and think nothing of it. On the bench though, 10 and I'm about done.

For travelling with reloads, I understand some places can be difficult about it in terms of import. I've never heard of an outfitter banning their use on a hunt though. The best option seems to be to retain a factory ammo box and just transport your reloads in that. Job done.

 

[zambezi]

Off hand I regularly shoot 20 rounds through mine in a session and think nothing of it. On the bench though, 10 and I'm about done.

Same. It is a lovely caliber to shoot. Up from a .30 cal, but no monster. Particularly shooting off sticks or free hand. With your body anchored to a seat whilst bench shooting, your body is less free to roll with the recoil.

 

[BigPat]

When I first got mine I went to the range at Kynamco and shot 43 rounds off the bench......won’t be doing that again! Felt it for days.

But put it on the sticks and it’s an absolute dream to shoot.

 

[Alistair]

When I first got mine I went to the range at Kynamco and shot 43 rounds off the bench......won’t be doing that again! Felt it for days.

But put it on the sticks and it’s an absolute dream to shoot.

Heh. I did this too.

Sorted out a range of charges for load development and rocked up with 50 300gr rounds to test. "Oh, I'll just quickly shoot these off the bench for groups and go from there" says I to the RO.

Had a bit more respect for the thing after that. Absolutely fine if you can roll with it though.

 

[Namman]

Heh. I did this too.

Sorted out a range of charges for load development and rocked up with 50 300gr rounds to test. "Oh, I'll just quickly shoot these off the bench for groups and go from there" says I to the RO.

Had a bit more respect for the thing after that. Absolutely fine if you can roll with it though.

Great calibre! Have had great sport in Africa over the years . Two of us , using .375's for jackals and other vermin, after the bigger stuff was taken. As you said you have to roll with it.
Going back to the original post I would definitely crimp .375 for use in double rifles (as with revolvers). With magazine rifles and no crimp, all you get is "dubbed" noses on your bullets, the bullets can't really move anywhere because of the front of the magazine and all my loads are compressed so they can't move back into the case . There is a nice long neck with this case as well.
If you do crimp (and if you don't also! ) you should run every round through the magazine and into the chamber to make sure there are no chambering/feeding issues, obviously with full safety considerations.

 

[Selous]

I spent an hour or so pre purchase testing a nice 375 this morning and fired one shot with four of the crimped rounds in the magazine. Interestingly all 4 fired rounds removed from the magazine showed signs of the bullets being pushed back into the case, some so that the cannelure was not visible any more. I guess a factory crimp die is beckoning...

 

[Redneck]

I`ve not experienced this at all with my handloads although I have felt the neck tension from the Lee Collet die is quite tight. I have a Lee Crimp die and this thread is making me think I should experiment.

Cheers Gents

 

[Stalker62]

I spent an hour or so pre purchase testing a nice 375 this morning and fired one shot with four of the crimped rounds in the magazine. Interestingly all 4 fired rounds removed from the magazine showed signs of the bullets being pushed back into the case, some so that the cannelure was not visible any more. I guess a factory crimp die is beckoning...

Still bear the "Sniper scar" from the first time I pulled the trigger on mine. Never mind crimping the bullets - tuck that bugger in and hold on tight...

 

[Namman]

I spent an hour or so pre purchase testing a nice 375 this morning and fired one shot with four of the crimped rounds in the magazine. Interestingly all 4 fired rounds removed from the magazine showed signs of the bullets being pushed back into the case, some so that the cannelure was not visible any more. I guess a factory crimp die is beckoning...

What make was the ammo? Was this factory ammo ? It would appear that despite a crimp there was inadequate neck tension. My homeloads are heavily compressed so there is no possibility of bullets being pushed back into the case. I am more concerned about bullets backing out of the case due to inertia.

 

[bowji john]

On recoil it is not the round in the mag moving - it is the rifle and mag which then clouts the nose of the round and (can) cause bullet getting pushed back into case

 

[Selous]

What make was the ammo? Was this factory ammo ? It would appear that despite a crimp there was inadequate neck tension. My homeloads are heavily compressed so there is no possibility of bullets being pushed back into the case. I am more concerned about bullets backing out of the case due to inertia.

These were mild to moderate home loads with 270g hornady interlock SP and N140 and new winchester cases. I thought I had put a fair bit of crimp on them ... clearly not enough!!

 

[Namman]

On recoil it is not the round in the mag moving - it is the rifle and mag which then clouts the nose of the round and (can) cause bullet getting pushed back into case

There are twi forces at work here.
One as you said is the mag clouting the round, the other is inertia.This is where the rifle recoils and the effect is of the bullet standing still.Those of us who used revolvers know this can be a real issue and can jam the cylinder.I think a lot depends on how strong the magazine spring is.

 

[bowji john]

With recoil in a rifle I can only see one accelerating force at play - in the direction of bullet to case head applied by the bullet's nose in contact with the moving inner edge of the front of the mag (as the round itself is pretty much free floating within the mag)

There is then a decelerating force in the opposite direction as the round comes to a stop - this time acting from case head to bullet as the case head interacts with the inner edge of the rear of the mag - both forces have a compressing effect on the round

I cant see where there is a force being applied that can separate bullet from case, or elongation of the round

Can you explain?

Inertia is not a force it is a property of an object to remain in an unchanged state unless acted on by a force

I can see it being a problem with a revolver though because the accelerating force is not acting on the nose of the round but on the rim of the case - THAT might well cause some separation between case and bullet because of the reluctance of the bullet to be pulled along by the case (it's inertia) - but not with a rifle

 

[Namman]

With recoil in a rifle I can only see one accelerating force at play - in the direction of bullet to case head applied by the bullet's nose in contact with the moving inner edge of the front of the mag (as the round itself is pretty much free floating within the mag)

There is then a decelerating force in the opposite direction as the round comes to a stop - this time acting from case head to bullet as the case head interacts with the inner edge of the rear of the mag - both forces have a compressing effect on the round

I cant see where there is a force being applied that can separate bullet from case, or elongation of the round

Can you explain?

Inertia is not a force it is a property of an object to remain in an unchanged state unless acted on by a force

I can see it being a problem with a revolver though because the accelerating force is not acting on the nose of the round but on the rim of the case - THAT might well cause some separation between case and bullet because of the reluctance of the bullet to be pulled along by the case (it's inertia) - but not with a rifle

Thanks for the physics lesson!
I agree with a lot of what you say regarding the contact with the recoiling magazine front edge. This is obviously why lead tips and some polymer tips get damaged. However the comments re revolvers and double rifles still apply. The inertia of the projectile is not overcome by the force of recoil and hence the firearms recoils away from the bullet.
As I said before I have never had this happen in my .375's (4 of in 40 years ) but I have seen plenty of battered bullet noses. My .458 , using 500gr bullets does show the phenomenon of bullets leaving the case to produce an elongated round.
It was always good advice with double rifles to change the rounds around so that the same round was not always in the unused barrel.
In the case of revolvers you mentioned , the force of recoil acts on the whole firearm and case but the heavy bullet's inertia "leaves it behind on recoil", thus lengthening the cartridge and potentially jamming the cylinder. Nothing to do with the rim of the case.
When we had revolvers this was a common issue, --- not enough crimp.