Crimping Question

[teddy salad]

I was shooting some .303 British reloads in my Enfield jungle carbine this weekend, and had two rounds that didn't feed into the breech smoothly. I worked the bolt and popped them out only to notice that the bullet had become recessed into the case by about a quarter of an inch. Further inspection showed that some other bullets could be recessed if pushed hard enough.

I had full-length and neck-sized the rounds, then crimped them with a Lee Factory Crimp during the reloading process, following the instruction sheet to the letter. That said, I'm not sure how to tell if it is crimped correctly (or enough).

Is there some sort of guideline or rule-of-thumb to follow when crimping? Should it be visibly crimped? If so, how far down?

[teddy salad]

I'm using Hornady XTP 311 diameter and they're not cannellured. They are the ones I was using for my 7.62x54r reloads, and now that you mentioned it that may have not been a good idea. Looking at Hornady's line of bullets, they have Interlock bullets (with cannellure) in 312 diameter specifically indicated for 303 Brit and 7.7 japanese. Think maybe it's time to give those a try. Thanks for pointing out the cannelure - I think in this case it would really help.

[olafpfj]

I have the same issue. I've been using hornady 174gr FMJ for both 7.62x54r and 303. They are NOT. 312" as advertised. The box lists something smaller, .3105" I think. Not a problem with my mosin but my No.4 MKI does not like them and they aren't very tight in the case. I'm looking into some Speers and hope they are actually .312".

On another note try slugging your bore and you'll see a big difference between a mosin (mine isn't a Finnish. 308) and an enfield. Then again my enfield may just be that shot out

[MoJo]

Cast bullets can be sized to fit your bore. Of course then you'll have something else to do with your spare time.

[teddy salad]

Cast bullets can be sized to fit your bore. Of course then you'll have something else to do with your spare time.

LOL...my wife will be thrilled to hear that.

[SeaHawk]

It appears to me that the first problem should be addressed first:

I was shooting some .303 British reloads in my Enfield jungle carbine this weekend, and had two rounds that didn't feed into the breech smoothly.

I would suggest you load two or three dummy rounds and try to solve the feeding problem. Things to look for would be the bullet shape, COL or burrs on the feed rails etc. Crimping is important but will not prevent bullet setback if the round encounters a solid steel bulkhead on it's way to the chamber. Since your bullets appear to be loosely fitted in the case neck you should check the diameter of your expander ball. Expander ball diameter should be .002 or .003 smaller than the diameter of bullet you are loading. If your expander is the correct diameter you may have some brass which has been annealed excessively.


The Lee factory crimp should definitely be visible and cannelure is not required. Crimp the least amount which will secure the bullet satisfactorily. I normally start with trying to crimp a little less than half the thickness of the brass. If you can get the rounds to feed smoothly you may not need a crimp at all.

New production Winchester 7.62 X 39 neck diameter with bullet seated = .335. Diameter of the neck on the factory crimp = .324 . Neck wall thickness of new unfired Winchester 7.62 X 39 brass = .012 . So the crimp is approximately the thickness of the brass.

Lee Factory Crimp

The .303 is a fun gun to shoot. I think you will really enjoy it once you get the little kinks smoothed out.

[teddy salad]

Thanks, Seahawk, that's a lot of good information. I'll get the calipers out tonight and measure that expander ball. And the new Hornady bullets I bought have a rounded nose so I'll throw together some dummy rounds and check the feed. That alone may do the trick - the original bullets I used were hollowpoints.