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Post by HMC710 on Feb 1, 2011 20:15:34 GMT -5
240 SMK's back in stock at Midway. on order......
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Post by HMC710 on Feb 12, 2011 20:12:15 GMT -5
Made a throating reamer today for my 1:8 blrs. Made the reamer to .3085 dia. I mic'd my PTG reamer to get a feel for what throat it was producing. The PTG cutting surface starts at .300" dia and increases to .310" dia for a length of .465". Hmm. OK, this is not a target rifle, this is a go bang rifle. Remember the posts on bullet diameters? I'm getting .3065. The PTG reamer explains why I can run some of the longer bullets without throating, a surplus bullet travels almost .250" before it reaches the rifling. I tried my throater and ran it in a bit. Will try and seat some long bullets and see what things look like. One thing I didn't do is mic my original reamer that I made a couple yrs ago, I'll have to do that. Looks like I might have to call Dave and talk Tok Match reamers.......
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Post by HMC710 on Feb 15, 2011 17:57:14 GMT -5
Using the Hornady 180 gr SPBT I checked the throat on my 1:8 brl. I just dropped the bullet into the chamber and measured from there. I could load the 180's out to about 1.85 OAL without issue with a stock chamber. From my measurements on the throated barrel my new OAL is 1.973" I have not ordered the 240 SMK's so I'll have to do that and see if I want to make some changes.
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Post by HMC710 on Feb 21, 2011 19:40:05 GMT -5
Got the 240 SMK's in today. 1.5960" long! The Hornady 180SPBT I was using are 1.2655" long Drew up some plans and with max length and 100% neck bearing I got about 2.195" OAL with Starline brass. Measurments with the throat I did the other day was 1.973" OAL with the 180's and 1.9255" with the SMK's. That explains why I could get so far out with the Hornady's, different ogive. Chucked up the barrel and indicated the throat cut line and ran it in. Talk about blind faith, I had no idea when the throater was cutting at all. so much for sneaking up on it.........2.195" is what it is. Haven't run QL yet to see how much powder this is going to take, but I've maxed out case capacity with the 240's. I don't even remember what I ran in the 180's anymore...... Well, off to the loading bench....... OK, here's a pic......
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Post by HMC710 on Feb 28, 2011 7:40:52 GMT -5
Loaded up the 240 SMK's for testing this weekend. My load was 7.3 gr of Lil Gun. OAL starting point was 2.195". Cleaned everything up and ran 2 loads for function testings loaded singularly. Gas system was stock Tok system and had a H3 carbine set up, no forend, sand bag up front, none in back. Bolt locked back with authority and case ejected strongly. Target was at 50yds and using my Burris red dot. Shots were at 10 oclock in the 8 ring 1/2" apart. Did not have the chrony set up, but there was no "crack" when shooting. QL predicted 1030 fps, 70% case fill, 21.6ksi. Cleaned things up and loaded 3 more of the same load. Checked fit in my Colt 5.56 green follower mag, Colt 7.62x39 mag, and Cproducts 5.56 black follower mag. The Colt green follower seemed to orientate the long rounds the best so I stuck the 7.62x39 mag in with 1 round. Dropped the bolt and the round fed. Fired 3 rounds, one round fed at a time, dropping the bolt to feed. Group opened up to about an inch. Cleaned things up again. Loaded up 5 at 2.210" oal, made a sight adjustment, and fired singularly 3 rounds. Loaded last 2 in the mag to check feed and function. Fired both rounds fed from mag. Group had 3 rounds in 3/8" with the other 2 opening it up to 3/4". Cleaned things up and repeated, same results. I did not try any Surplus ammo, wanted things to stay nice and clean. I was using one of my soldered gas blocks and I cracked the solder joint at some point so I'm going to pull it apart, weld the gas block and reassemble with a fore end and scope to check again. Will do some more Lil Gun loads and try some H335 to get 100% case capacity.
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Post by HMC710 on Mar 6, 2011 14:05:12 GMT -5
Got a chance to do some more shooting today. Loaded up 10.2 gr of H335 with the SMK and some other Lil gun loads of 180 SP & the VLD's I turned on the lathe. The 1:8 barrel definately helped on the stabilization of the VLDs. Didn't set up the chrony, just cleared the snow off the bench and hooked up the brass catcher. I put a welded gas block on the upper with a rifle length FF tube, A2 stock w/rifle buffer spring, and a compact Burris 2-7 that I picked up a while back but never mounted. Used a "universal" UTG 1 pc mount. It has a rail adapter on it that comes off and you can put it on a carry handle. Groups with everything were in the 3/4" to 1"-1/2" range at 50 yards. Shot 6 rounds of 3 different loads. Cleaned things up between each 3. After being disappointed with these results, loaded up 5 rounds of Tok Polish. Function was good and got the same 1+" group. After I finish up with the PPC, going to pull that scope off and try the SMK's again.
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Post by HMC710 on Mar 11, 2011 16:16:53 GMT -5
Doing a couple more 1:8 brls. Going to touch up my original reamer and see what happens. Have more blanks on order....
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Post by HMC710 on Mar 14, 2011 6:40:34 GMT -5
Ran a couple of mags of surplus through the 1:8 throated barrel. I used both a stock rifle buffer system and my light carbine buffer to see if there was any difference and it was ejecting the cases a few inches farther. Was getting a little bit of drag on the gas system so we are going to look at our jig set up on that. The dueling trees didn't stand a chance at 50 yards.
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Post by 22boomer on May 18, 2011 10:08:41 GMT -5
I went back to read this thread and wondered what is the difference between the 300 blackout shooting heavy bullets subsonic and the 7.62X25 shooting heavy bullets subsonic? As far as subsonic goes I was wondering if the 7.62X25 could just about match the 300 blackout. I can imagine the 300 blackout has the advantage of being used supersonic with 110gr to 125gr bullets for game like deer which makes the 300 blackout more versatile but for subsonics is the 300blackout that much better than the 7.62X25?
I found on the Starline 7.62 Tok brass that it's a hair shorter than the Sellier&Bellot 7.62 Tok brass but the Starline 30 Mauser is the same as the 7.62 S&B brass. Problem is Starline is a bit hit and miss with making the 30 mauser brass. I've had good luck with shooting the Starline 30 mauser brass because it comes up with a longer neck and holds the bullets better.
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Post by greywuuf on May 19, 2011 1:49:23 GMT -5
or have a "throater" well ok a necker ream made and use .223 brass and make an old timey looking cartridge with an extended neck on the standard 7.62x 25 body. interesting discussion about that kind of thing on a Cast bullet forum I used to frequent. Cast slugs work best in heavy (for caliber) weights and with long necks to cover lube grooves, so a perusal of the older target rounds often turns up some interesting candidates.
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Post by HMC710 on May 19, 2011 5:51:11 GMT -5
Subsonic is subsonic..... it all comes down to packaging. All the Blackout is doing is trying to standardize the 300Place-A-Name-Here, which it looks like they have done successfully. Now if the builders can agree on a gas location....
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Post by 22boomer on May 19, 2011 11:34:21 GMT -5
for me it's a matter of economy -- just cheaper to load smaller cartridges. I shoot 7.62X25 in my HMC upper and save the brass (S&B brass) and reuse it for my other 7.62X25 based rounds. Too bad the milsurp 7.62 Tok ammo is burdan primed -- I've tried reforming it just for the heck of it and most will reform really nice but it's worthless.
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Post by 22boomer on Jun 6, 2015 18:15:43 GMT -5
Tim, I know this thread is kinda old but since I got that no-gas barrel from you I tried some 200gr SMK's with 7.0gr of Lil Gun and they shot just fine but I have no idea at this time what velocity range they might be in.Do you have any idea what the velocity of your 240SMK's where back when you were shooting them?
I honestly don't know what the actual amount of throat there is on that no-gas barrel so I'll just have to run some long rounds in to see what just fits. The cartridges with the 200gr SMK's had a COL of 1.85" and showed no signs of pressure.
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Post by HMC710 on Jun 7, 2015 8:40:15 GMT -5
7gr of Lil Gun should put you in the sub ball park, maybe on the high side with the 200's. You'll tell when you get the crack when shooting. Run your OAL out until the rounds won't seat, you should have about .5" more to go with the SMK, that will also drop pressure / vel until you hit the lands.
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Post by 22boomer on Jun 7, 2015 12:10:33 GMT -5
Tim, thanks for the info. I was hoping I might be subsonic but won't get a chance to shoot through the chrony for another month.
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