Anyone come up with a action Cycling Subsonic Load yet

[LRRPF52]

TX,


I think I came upon what was happening with the Lee dies. I understand that back last year in the spring, I believe, the 6.5 Grendel bolts were changed by Alexander to what is called a Type II bolt. The Type II bolt has .010 of bolt face clearance. Lee dies may well have changed their sizer to match because the Lee dies I bought were advertised as Alexander Arms dies. Now, the 6.5 Sporter by Model 1 and the 264 LBC both use a Type 1 bolt face with a standard .003 or close to that, bolt face clearance. I kept having chambering problems that made no sense until I went through buying a new barrel with a guy that just bought a new Black Hole barrel and ran into the question, do you want a Type I or a II.......


Ed

Alexander Arms has not changed the bolt design, unless there's something I missed. They have always used the original Colt 7.62x39 bolt design, which has a .135" bolt face depth.

Many after-market companies started making their own 7.62x39 bolts with the same depth as a 5.56 bolt, which is .124", hence the .011" difference.

BHW started out with their Type I bolt as a .124" face depth, and have now gone to a .135" depth for the Type II.

[sneaky one]

Nice vids., TX. Try h20 jugs --3 rows, 10 deep. Or increase the size of the jugs,( no pun intended)...... or add some thick rubber-etc around the edges. to capture- or bounce back-inward? the ones that exit the side.-they are real slow at that point. I used a wheelbarrow to haul 2 loads of 30 juggs last May to the range= phew ! Plus all the shooting stuff=4 trips.

[txgunner00]

I would have stacked them deeper but that's all I had. I'm doing research into doing my own ballistics gel test. That should be fun.

[txgunner00]

Though I'd share a I little data I collected late last night (I have a bullet trap in my garage) I put a heavy crimp with a Lee factory crimp die on a few loads to see the effect. Non-fire formed cases came out a little less dirty and slightly better formed compared to uncrimped non-fire formed brass. (bottom 3 in the pic)

I also loaded a few using Winchester fire formed brass and crimped (top 3 in the pic). The increased case capacity / decreased load density had an adverse affect as they did not cycle- ejected the spent case but didn't feed. I need to play with the seating depth a bit to see if that helps. These were seated an 2.220. They do come out slightly cleaner than non-fire formed brass but still do not get a complete seal as evidenced by the soot around the case rim.



The cleanliness of the case is really a matter of observation of how the round is performing in the chamber. As long as there isn't any unburnt powder present it doesn't concern me much because adding a suppressor will make them come out black.

[Variable]

Yeah, with a can they'll likely look like #2--#6 in this pic. The farther down the mag they are the dirtier they'll be as the blowback from the can will deposit crap on them before they're even fired.

[txgunner00]

Here's another vid from today shooting water jugs. Passed through 5. Still wasn't able to recover the bullet because it yawed upwards and went over the berm.

[video=youtube;JOcpYX5DXMo]http://www.youtube.com/watch?v=JOcpYX5DXMo[/video]


http://youtu.be/JOcpYX5DXMo

Summary of the 5 jugs
1st- pretty much straight through, exit hole a little oblong.
2nd- entrance slightly larger than round, exit hole about 3/4" long, jug ruptured
3rd- entrance 3/4", exit over 1", bullet appears to be rotated 90 deg., jug severely ruptured
4th - over 1", entrance side of jug split, 1" exit
5th - 1" entrance & exit at top of jug.

[txgunner00]

Just a quick clip of a SS triple tap.

[video=youtube;dw0VA9axrt0]http://www.youtube.com/watch?v=dw0VA9axrt0[/video]

Nevermind my fishing hat...

I have some more chrono data also. I'll get it up as soon as I can organize it.


http://youtu.be/dw0VA9axrt0

[Variable]

[whispers]Pssst... Us Safari browsin' iPad impaired folks can't see the embedded vids on this board... Got any links?[/whispers]

[mongoosesnipe]

21" with a mid length gas system? Did you order that for a specific reason? Please share.

The suppressor will absolutely help but I don't have one the correct size yet. I'm waiting on a form 1 so I can make my own.

I like to use mid length gas systems with low profile gas blocks and rifle length float tubes gives a nice clean profile on my ar builds mostly just a personal preference and the use of an adjustable gas block allows me to cycle just about any load a habit I picked up on my whisper build

[txgunner00]

I like to use mid length gas systems with low profile gas blocks and rifle length float tubes gives a nice clean profile on my ar builds mostly just a personal preference and the use of an adjustable gas block allows me to cycle just about any load a habit I picked up on my whisper build

You should have no problem developing a SS load then. Lots of dwell time on that gas system.

[txgunner00]

[whispers]Pssst... Us Safari browsin' iPad impaired folks can't see the embedded vids on this board... Got any links?[/whispers]

Forgot... fixed.

[txgunner00]

I played with the seating depth and crimping a little this weekend. Here's the info.



I seated as far back as the bullet would allow (2.160") without falling into the case. The bullets were instable and velocities erratic. Next I'll try pushing them out as far as the chamber will allow.

The crimping seemed to not affect accuracy or velocity much but made improved how well the non-fire formed brass formed to the chamber and they came out significantly cleaner. I'll post pics of the brass later.

[txgunner00]

If anyone is having a hard time reading the charts and wants a PDF version PM me your e-mail address.

[Dacapster]

dryer lint makes a good filler.

[txgunner00]

dryer lint makes a good filler.

I've have used various stuff in the past for fillers in fire forming loads but never in a gas gun, especially an AR. Unburnt debris can build up in the gas system and KABOOM.

All of these loads have been without fillers and I'm slowly dialing in on a combination that will perform consistent enough for this application.

[txgunner00]

Here some pics of the brass. All crimped. As you can see they are much cleaner and better formed than non-crimped I've posted previously. The Remington 9 1/2 primers are performing the best out of the 3 I've tried so far. Lowest average extreme spreads and cleanest cases. Unfortunately I'm out of Rem 9 1/2 and I just bought a brick of CCI250's. Got to spend some more $$ at the local gun shop. Oh well, I'm sure I'll use the CCI's somewhere.

[Variable]

Forgot... fixed.

Thanks. Great vids! Especially liked the ones of the youngin's having a great time!

What were those targets? White spray paint?

Back on topic--- I wonder if the 160's would tumble quicker (and to more dramatic effect) if you were to "spoon tip" the bullets?

You probably already know about them, but for any folks unfamiliar with spoon tips there is a decent description of them here:http://guns.connect.fi/gow/QA10.html towards the bottom of the page...

[txgunner00]

Thanks. I love taking my daughters to shoot with me and I'm very fortunate to have access to a place where I can do so. My 7 year old is well on her way to being able to out shoot me. She didn't miss once on that trip.

The targets were cheap shaving cream cans. They put on a good show and the girls like to play in it afterward.

I do have plans to experiment with the bullets a bit but haven't gotten to it yet. I was vaguely familiar with spoon tips but didn't know much detail on the subject. That link will save me some time. Thanks. One thing I have put some thought into is making a forming die to swage the tips into hollow points. I recently bought a lathe so I can do it all in house, literally.

[txgunner00]

I did a little measuring on the .268" blemished bullets I bought from Grafs a while back. Unfortunately they will not work in my chamber. This is what I got when I was trying to find where they hit the lands.



Looks to me like its not even making it to the lands.

[JASmith]

It looks like you are catching at the start of the throat.

While I don't have a credible Grendel chamber drawing, I was able to look at the SAAMI throat diameter for the .264 Win Mag (.268") and the CIP throat diameter for the 6.5X55 (.269").

It looks like you have what might be a .268+ bullet trying to go into a .268- hole. (AKA an interference fit.)