Home Forums Reloading Big Game Rifles Noob crimping questions

Man, this reloading stuff is sure confusing. I’ve never seen a collection of material that consistently contradicts itself. I’m brand new at this this stuff, super gullible, and not sure what to believe. Every source swears imminent death should you veer from that particular manual or source.

I’m starting to reload for the following rifles:
7mmRM In a tikka action
9.3x62 in an HVA 1600 action
.375 H&H Ackley in a Sako AV action
30-378 Weatherby In a Weatherby action

My question revolves on weather to crimp or not to crimp, and where to crimp. COAL is different for just about every bullet/powder combination. Some sources say all these cartridges need/should be crimped. Some say that you need to precisely follow published COALs. Some say you can crimp your bullet anywhere if you trim your cases to the same length. Some say to seat your bullet out far as possible to be able to fit in your magazine to achieve best accuracy. Others say to find the lands and either seat your bullet on the lands or just off them. Some say you should only seat and crimp your bullet at the cannelure/crimping groove.

What’s the deal??

The problem is that I can’t satisfy all these rules. Ie, the lands for my 9.3 are further than the magazine would allow, and if I were to stay at the most common published COAL of 3.290, the crimping groove on my bullet is 1/4” from the case mouth. All sources say I should crimp this round with my 58g of varget or 62g of big game. How do I not die?

Thanks for the replies. I’m a noob and may not understand all your answers, but I’ll try. And I’m still looking for a safety catch spring for that HVA1600. Thanks.

If the bullet/cartridge chambering has a long bearing surface, crimping is not necessary.
I aim, for loads in those beyond your 7 mm rem mag, to fill the case to where the bullet won't get pushed further into the case by recoil.
Then, I'll crimp into an already existing cannelure. That keeps the bullet from moving out under recoil. (Assume full magazines here.)
Engineers design cannelures, it seems, to fit "good" or factory loads, but crimping is never mandatory. Good luck, and stick with data.
Learn as you go, be cautious and safe, and remember all rifles used to be handloaded.

There is a lot that can be discussed here, but specific to crimping, here are a couple of thoughts for you.

There are two types of crimps; "roll" crimps and "stab" crimps.

Crimp #1--Roll crimps are what you see most often used by typical die sets. The seater die use a radius at the top of the case neck...as the case is pushed into the die, the brass is rolled inwards. Typically, it is best that you have to have a cannelure for this to work so that there is somewhere for the brass to roll into. If there isn't a cannelure (or your cannelure ends up above or below your case neck) and you try to roll crimp, you will often result in a buckled case shoulder.

--If your trim lengths are not uniform, a short case will not meet the radius of the die and there will be no crimp.

--If your trim lengths are not uniform, a long case will meet the radius and jam more brass than necessary, resulting in a buckled case shoulder.

As you mention about seating depths, sometimes the OAL doesn't allow you to put the cannelure in alignment with the case mouth which really prevents the use of a roll crimp.


Crimp #2--Stab crimps are what you often see used on factory ammunition and the only die I am aware of for reloaders that immitates this, is Lee's "Factory Crimp Die." This die uses a "stab" type crimp via a collet that squeezes at the top of the ram's upstroke. This type of crimp works regardless of case length and will not buckle case shoulders.


Of the two crimp types, I much prefer to use Lee's die just because it is much more forgiving to use. Cannelure, no cannelure, long brass, short brass, soft crimp, hard crimp...it is a pretty neat die.

Since you are starting out, I would recommend you set your dies up so they do not crimp....at least until you get your feet under you with the various processes. As Agazain mentions, recoil or compressed cases may require some crimp. If you find your bullets are moving as a result of either of these two issues, start experimenting with a crimp. Till then, I would forego the effort.

IME crimping is only necessary to prevent bullet movement in or out. Sometimes bullets will start moving out from recoil. Bullets can be pushed in if the magazine is a tubular type like in a lever action or sometimes feeding a semi-auto.

I’d also add that at times, a crimp can really make a difference accuracy wise. I’ve had mixed success crimping....but it has made a difference, particularly with slow powders. I generally only go do down the crimping rabbit hole when bullets are moving due to super compressed loads. As a new comer, I would not mess with crimping as it’s fairly rare to be unable to find a suitable load that requires it.

One of the best tools a reloader can have is a chronograph. Without one, it’s very difficult to guage velocity and have a sense of when you’re pushing too hard.

For what it’s worth, I pulled my hair out trying to get a 30-378 to match factory velocity and accuracy at the same.... Good luck!

I’ve never crimped a 7 mag load, don’t have any of the big boys you listed. The Lee die works really well on some cartridges I load.

I load quite a few different calibers and the only thing I crimp is for handguns and tube fed lever guns. If ya can't load as long as ya would like to all I've done is load just short enough to work in the magazine.

How much "banging around" are your rounds subjected to before chambering?