Seating/Crimping the .338 Win mag?

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the rifleman

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I am doing some work up loads for my .338 win mag. It would appear that I am not able to seat the bullet to allow it to lie close to the rifling,(Winchester M70) as it would then be to long to fit in the magazine. This being the case, should I just move it as far forward as I can, or not worry about it, and just seat the bullet to the crimp line.

Is it really neccesary to crimp the .338 to allow for recoil, or will the bullet stay tight in the case, just with neck seating pressure. I have heard that the recoil on the .338 may cause bullet slippage, but I'd like to hear it first hand from some fellow reloaders familiar with this calibre.

Thanks:)
 
I've reloaded my 338win for years and I've never needed to crimp them. The recoil flattens the tips of the rounds in the mag sometimes but not much and I've never seen the bullets set back in the case.
 
I odn't see any need to crimp most rifle cartridges, I just make sure the neck tension is good.

For you r OAL proble, just sea tthem to where they are most acccurate within the confines of your magazine. Usually, but not always, that is as long as the mag azllows- but not so long that they are sticking!:p
 
HeadDamage said:
I've reloaded my 338win for years and I've never needed to crimp them. The recoil flattens the tips of the rounds in the mag sometimes but not much and I've never seen the bullets set back in the case.
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This has been my experience with my 338 too. I've never had the bullets back into the case.
 
With any cartridge..just use the old method of forcing the bullet in a loaded round down on a bench, if it doesn't slip under your weight you're good to go.
The exceptions would be very heavy bullets in Str. cases under heavy recoil...I firmly crimp all my smokeless, 44Mag, 45 Colt, and 45/70 loads.
 
I use a lee factory crimp die for all bullets I cannot seat into the lands. The rationale behind this is that crimping ensures a consistent let-off pressure, in a similar way that seating into the lands does. Crimped cartridges usually do offer a measureable increase in shot-to-shot velocity consistency. This doesn't always lead to increased accuracy, but I've never seen it HURT accuracy either
 
I crimp all my hunting loads in my ruger .338 mag... in my rifle, accuracy with it crimped is better than non crimped in all bullet weights from 175 to 275 gr.......

hs4570.........your mileage may vary.
 
hs4570 said:
I crimp all my hunting loads in my ruger .338 mag... in my rifle, accuracy with it crimped is better than non crimped in all bullet weights from 175 to 275 gr.......hs4570.........your mileage may vary.
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How much better groups do you get from crimping vs non=crimped. Are we talking several inches?
 
Mr Rifleman

The accuracy difference between crimped and uncrimped in my Ruger .338..........

Crimped with 200 gr. Hornady was 1.75 in/200yds/3shots ...uncrimped just under 3 inches...........avg velocities about 2950 fps l

Hornady 250 gr Crimped at 200 yds/3shots.......1.58 inch
Uncrimped 250 gr at 200 yds/3 shots......2.25 inch........avg. vel.2680 fps

...........Bushnell 6 to 18X utilised for all load testing



hs4570............your mileage may vary
 
hs4570 said:
The accuracy difference between crimped and uncrimped in my Ruger .338..........

Crimped with 200 gr. Hornady was 1.75 in/200yds/3shots ...uncrimped just under 3 inches...........avg velocities about 2950 fps l

Hornady 250 gr Crimped at 200 yds/3shots.......1.58 inch
Uncrimped 250 gr at 200 yds/3 shots......2.25 inch........avg. vel.2680 fps

...........Bushnell 6 to 18X utilised for all load testing



hs4570............your mileage may vary
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Boy, that is good statistical data and it speaks loudly for crimping. I've not done such testing, but I don't crimp my .338. I seat it about 0.075" from the lands and it shoots under 1/2" @ 100 yds. I also don't suffer bullet end damage. My conclusion is that seating closer to the lands may in some cases by over rated.
 
I crimp all my hunting ammo, but I only choose bullets with canulars. Conversely, I seat target bullets into the lands. Both systems produce uniform bullet pull, and the post above seems to support that premise, with regards to crimping.

Hunting ammo should be loaded with reliable feeding in mind, rather than for extreme accuracy. I full length resize rather than neck resize, and I seat the bullets short enough to operate in the box magazine without hanging up. After reloading, I run my ammo through the rifle to ensure that it feeds properly, and any glitches are put aside for range work, or are disassembled and reloaded. Should I need to fire a number of rounds quickly, I know I can do so without my rifle tying up.
 
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