SUB-SONIC Grendel loads

[txgunner00]

That's Ed's (Rapier) load described above.

I have the powder, bullets & brass. Now I just need the time to put the together and get to the range. Been too busy with the house & kid's birthdays.

[hm2 clark]

Please keep us informed of your progress. If you guys ever come up with a quiet 160gr load you think woulld be useful when hunting, I would like to try it out. For me it would not have to run in a semi or full auto gut, just a encore pistol or bolt rifle. My criteria for a "good" subsonic round woud be (1) is it accurate to 75 yards. and (2) will it expand/kill out to 75 yards and then maybe (3) how much does it recoil.

[fanofflyn]

I checked on the Hornady website, and they have roundnose .264 160 grain bullets also.

http://www.hornady.com/store/6.5mm-.264-160-gr-RN/

[txgunner00]

Those are the bullets Rapier and I have been using.

Hm2 - unless you are using a suppressor, the shooter won't notice a big difference in sound. Someone off in the distance would be less likely to hear you because of lack of sonic crack and reduced report.

[hm2 clark]

I have used a borrowed suppressor for hunting but a quiet pop rather than a loud BANG is mostly about my respect for the people who let me hunt their land. When a rancher is sitting down for supper with his family, or they are just getting up in the morning a loud unexpected supersonic CRACK can make them flinch , and therby make me less welcome tomorrow morning at the crack of dawn. I text them entering entering and leaving their properity not call. I leave my truck at the road side and walk, not drive in. I try to make my presence less noticable in their day to day life. Thats why I want a quiet round- for my host, not me.

[txgunner00]

Then this load should work for you. Once I have my load dialed in I intend to do some basic terminal ballistics testing. Hopefully sooner than later if I can manage.

[Raider1v1]

any luck finding a working subsonic load? I was going to start with some BLC2 and the 123gr Hornadys, but i have ZERO experience working up a load like that. and sorry for the question, but why is a heavier bullet preferred when working a subsonic load up?

edit - read through the page before and found it - http://www.65grendel.com/forum/showt...ll=1#post11629

[txgunner00]

LOL- I just responded you post on silencertalk. I see you found this on your own.

If schedule works out I plan to shoot my test loads using AA2015 this week.

[txgunner00]

Well, my AA2015 test loads didn't work as well as I hoped. 13 grains gave me an average velocity on 1009 with a SD of 35 which is OK. However they didn't function and the cases were fairly sooty. The bolt was thrown back further than any other SS load I tried but still not enough. This is most likely due to pressure dropping too much in the rifle length gas system.

I may try some tweaks on this load. Maybe drill out the flash holes and switch to a magnum primer to get a cleaner burn. Dunno yet.

Got to run.... More later.

[txgunner00]

I'm back. I think these loads may function when I get a suppressor on the rifle. I could also open up the gas port a bit and install an adjustable gas block. This barrel seems a little under-gassed anyway. I'm currently running an ar15 carrier and 2.6 oz carbine buffer. I tried a heavier buffer I had short stroking issues with full power loads.

[burnsome]

sounds like you're getting close txgunner00. keep up the good work and keep us posted as things progress

[txgunner00]

It appears that anyone interested in sub sonic loads for the Grendel would be well advised to work the load problem using Win 7.62x39 brass to start with. However a word of caution about the bullets, you must have sufficient clearance in the chamber neck area to allow for the increase in bullet diameter plus case neck thickness. I would suggest that you start with .264 bullets. Make very sure you have clearance to load the round without it sticking in the neck of the chamber, if sticky, use the 264 bullets only.

.

Another member here and I were discussing this project and I thought I would revisit this part of it. In an extreme case an oversize bullet could wedge it's self in the chamber preventing it from moving. It would be similar to an over max length case crimping into a bullet and locking it in place (illustrated here about 2/3 down http://www.hornady.com/ballistics-resource/internal ).

I measured the neck thickness of AA, Hornady, fire formed IMI and Winchester 7.62 brass. They all measured .010"-.012" except the Hornady which was .012"-.013". The Grendel chamber neck diameter is .300" so this should leave anywhere from .012" to .006" to spare (.300-.286-.013-.013). Now consider the LBC's neck is .295" and that reduces the minimum clearance down to .001". A dirty chamber or thicker case neck could spell disaster.

Now I may be way off in my thinking and/or math here so feel free to correct me if I'm wrong. I just want to bring it up for discussion before someone finds out the hard way.

[rcvisket]

Any news or updates for this?

[txgunner00]

I posted last in the other thread.

http://www.65grendel.com/forum/showthread.php?2271-Anyone-come-up-with-a-action-Cycling-Subsonic-Load-yet

[rcvisket]

Awesome. Thanks