How do semiauto`s handle hand loads, any tips

[jtoews80]

I have a few questions. I don`t own a semi auto centerfire rifle and won`t handload for them. My younger brother has one due to a disability and has been hassling me to load for it. It`s a 308 win, 742 Rem witha 2.5-10X40 Elite 4200.
I`m a bolt guy, the accuracy is better and I shoot mostly handloads. They`re easy to clean, they don`t jam, and to my mind, you shouldn`t need more than one shot per target.

And then I don`t have the urge to hammer off rounds and cook a barrel because it`s alot of fun. I get carried away enough with my lever 44 and semi 22.
Most of the time I have been loading Noslers 0.5-1 grain below max and some of my loads at max. I run sierra bullets within 0.5 of max usually unless the accuracy suffers. I`ve heard that semi`s in particular gas operated ones really don`t like heavy loads and could damage the action. Any tips for loading for semi`s.

JT.

 

[Woodycreek]

Gonna start loading for my DPMS AR-308 and need the same info. Thought about a grain or two off of book max on the high end to be safe.

 

[old #7]

Full length resize every time, COAL to SAAMI spec, and not too hot produces great groups out of my AR-15.
I have found that most feeding problems when using hand loads are caused by long COAL.

 

[JD338]

I have limited experience with semi autos. Shot M1 and M14 in competition and had a M742 carbine. The 742 was a 30-06, had a Vari X 1.5x5 scope and it shot under MOA at 100 yds with hand loads. I used a RCBS small base die and never had any cycling issues.
I think you should do just fine.

JD338

 

[Alaska]

308 Win

IMR 4895 works very well.............with 42.0 to 43.6.
165 Sierra BTHP.

Suggest using Small Base Sizer Die for the brass for the Rem 742 just like JD338 said!

 

[Guest]

The right dies are important. RCBS makes Small Base dies, and Hornady dies are pretty tight in terms of their sizing, so both will work, usually. Beyond that, the gas system takes a beating if you use slower powders, so as has been mentioned, stuff in the 4895 burn rate range is the best choice. Also, consider using stick powders if you can, because most of the ball stuff burns dirtier, and in a semi, that's bad. Beyond that, Old#7 hit it on the head with the COL kept at SAAMI to help with feeding. Expect to get dismal velocities, as the gas system really soaks up speed in my experience. I once wrote an article on loading for autoloaders, but decided to revise a portion of it prior to getting it published. Then the place it was going to be published went away. I may dust it off, revise it, and send it off to Handloader or something. It's pretty interesting reading.