OAL question

[jazzman]

Hello to all, First post to this forum.
I am a new reloader and have a question about OAL. I am using the Hornady XTP hollow points which have a crimp groove. My Lee modern reloading manual shows different OAL's depending on the type of powder and bullet weight used. I assume that the OAL will be fixed and cannot be changed when crimping into the groove, how can you vary the length to be sure you meet the minimum OAL. In the book it shows that using the 125 grain xtp the minimum OAL should be 1.437 with one type of powder and 1.455 with another type. Should I be concerned if the OAL's vary a few .01's. Also, can I put a roll crimp on lead bullets that do not have a crimp groove. Thanks for any help with these questions.

Jazzman

 

[db_tanker]

OAL is an established parameter done by SAAMI in most cases...

Generally you can find diffrent OAL's for diffrent bullets due to the magazine or the ogive of a given bullet. Some bullets are even made with two diffrent crimp grooves. As far as the diffrent powders with diffrent lengths...well...you won't find too much of that in your regular reloading manuals...Sierra has some diffrent lengths, but again, its due to diffrent bullets in the same weight class.

Remember, you seat your bullet to fit in a magazine or cycle in a particular action. If your shooting in a single shot, or perhaps a bolt rifle with a generous sized magazine, then you can seat your bullet out to get it closer to the rifling...don't have it touch the rifling...might cause a pressure spike...and those can be bad. You don't necessarily have to use the crimp groove...you can put crimps anywhere on that bullet. I have some 223 ammo that someone thought that there was somthing wrong with it, due to the cannelure was exposed more than usual...I explained that it was tailored to my Contender single shot...
Also, as far as I am concerned, as well as others on this board and all over the world...one reloading manual isn't a real good idea...get several...use them as reference, not as a bible...I don't have it at work, but I have the Hornady manual and can get you your specific data if you need it for a particular round...

Now, as far as variation in oal with same bullets and diffrent powders...that doesn't sound right...I don't understand how that could be useful or even safe in some cases, like revolvers.

And as far as lead bullets go...its fine to crimp it wherever. I do on several diffrent types...both a roll crimp and taper...I just use a light crimp, however...try not to distort the bullet if its a softer alloy.

Hope this helps alittle.

Darrell

 

[jazzman]

db_tanker,

Thanks for the explanation. I have been refering to the Lee modern reloading book but I also have the Lyman book and the Speer book. I believe in reading as much as possible. Glad to know I can crimp on lead bullets without a crimping groove. I am using Lee dies with the factory crimp die which should keep me from putting too much crimp on the bullets. I have just been loading dummy rounds to get the feel of it and will be ready to go live very shortly. Again thanks for the help,

Jazzman

 

[armoredman]

I had to go under reccomended OAL to get Meister 115gr LRN to function in my CZ PO1 due to it's notorious short chamber. If you do, be very careful - I went very light loads while I am experimenting with this....

 

[Mark whiz]

I concur with db_tanker.

OAL is very subjective............. as long as you don't exceed the maximum (except as explained for customizing to a particular gun) you are ok. But if you load them short, just make sure you work your load up slowly to prevent over-pressure.