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View Full Version : First build works, a few questions...


DougW
April 11, 2002, 13:53
Test fired my first build, an L1A1 on an Entreprise "file to fit" type 1. Pulled the trigger, goes bang, all is well. Fired 140 rounds, and here is what is happening.

I cut the barrel to 18" and went ahead and drilled the gas port out slightly. No muzzle thingie. The gas setting for the most reliable function right now is 1. Still an occasional FTE. After the session, I cleaned and inspected. There is a little carbon fowling around the gas adjustment piece. The gas tube is now a little loose. I tore down and cleaned and reassembled. The tube remains a little loose. Oh, I forgot to say I have a new Tapco gas piston, diameter is good. No fowling below the second hump.

I think the rifle is still a little tight, and the gas setting will go up with time. Is my thinking right, or should I suspect a little gas bleeding around the front of the tube somewhere? I spent 3 days filing and lapping the recuever to get the bolt carrier to move in the rails. BTW, the headspace is still good after first shooting.

I guess overall I am very pleased, but I do have some concerns over the gas setting. Any thoughts would be appreciated.

ByronF
April 11, 2002, 14:27
The full length tubes are almost always a little loose. The short ones are soldered in the gas block.

Byron

ratas calientes
April 11, 2002, 14:37
Good to see that you know how to properly describe the Entreprise "file to fit" receivers! :D :D :D

ByronF has it right. The gas tube will be slightly loose. Carbon fouling sounds about right. On the gas port, Gunplumber writes that most 18-inchers work with a 0.116, some need 0.118. (And most 16-inchers work with 0.118, and some need 0.120.)

I spent a lot more time than 3 days getting my Type 3 "filed to fit." It was one little thing after another, but now it just hums along!

So, what size is the gas port?
Did you build on a metric receiver?

Later -

Ratas

DougW
April 11, 2002, 15:08
ratas, I built on an inch reciever. Right now the port is at .109 if memory serves me. I am wondering if I need to go higher, or run her there for a while. I hope to shoot another 200 or 300 rounds this weekend. My shooting today was at an indoor range.

ratas calientes
April 12, 2002, 00:09
DougW -

Not much margin with a gas setting of 1. You can run it for a while and see if it smooths out any, or just "bite the bullet" :D and open it up some more.

You should also measure the diameter of your gas piston.

When I built my 16-incher, I opened it right up to 0.120 at the beginning. I did not want to keep going back to the range. It runs great on about a 5. I also miked my gas piston, and it was on the maximum side at 0.432.

Ratas

[ April 12, 2002: Message edited by: ratas calientes ]

DougW
April 12, 2002, 07:59
ratas, I descided to open the port up some more. I agree with you that there is not much wiggle room on a setting of 1. The new Tapco piston mic'ed at .431 I think (too early for brain work). Will shoot this one and it's sister L1 on Sunday. Will let you know. Thanks for your input.
Doug

DougW
April 14, 2002, 22:54
ratas, just wanted to let you know how the shoot in went today. The second L1 ("Matilda") shot 4" high 1" right on the first round. Had 2 mags that worked good, two that would not lock in. Gas setting on 3, and after 80 rounds she is still a little tight, but shoots great. Very happy with build #2.
The first, my rifle ("Shiela") gave me fits. First 40 rounds she was all over the place at 100 yards. Finally got her to settle down and got her shooting consistent 2" high centered at 100 yards. She finally functioned at 6 on the gas adjustment, but a funny thing happened when I cleaned her. The pin that locks the gas tube in had backed out about 1/3 the way, and I couldn't adjust in the field because I did not see the problem. Never heard of that before. I re-installed the pin and EVER SO SLIGHTLY straked both sides of the opening to try to keep the pin from comimg loose again (origional pin with the kit). The end result is that she will probably operate on a slightly higher setting, since some gas was blowing by.
At any rate, I could hit a paper plate at 100 yards 7 out of 10 times off hand. I am satisified with that performance. BTW, shooting South African. :D

ratas calientes
April 14, 2002, 23:31
DougW -

Great to hear that you have two rifles running. I thought you were working on only one. Silly me. (I have a few more kits, but they will have to wait for a while.)

The diameter on your gas piston sounds fine. I am guessing that the first rifle is the one that you cut down to 18 inches. As for the gas tube retaining pin, the gas regulator should keep it in place, unless it is way too short, and maybe a little too loose. I actually had to file about .005 to .010 off of mine, because it was just slightly too long, and I could not keep it from catching on the gas regulator, making it hard to turn. Sound like you got your's fixed.

If you were shooting off of a bench (sandbag, etc.), I remember reading a claim that the rifle was more accurate when one placed their hand between the handguards and the sandbag. I have never tried it. I'm probably not a good enough shot to make any difference. When I shoot at our city range, I do try to keep the sandbag near the center of the handguards, so it creates a little less "bending" on the barrel.

I have also shot the South African, and I was pleased with it (but my M14 did not like it at all - another story.) I just love shooting that Berdan primed stuff - no temptation to run around picking up fired brass.

Later -

Ratas

Michael64
April 15, 2002, 01:59
DougW

Good meeting you at Markethall. Good luck with that 3-gun shoot.

Chainsaw
April 15, 2002, 08:42
DougW
Sounds like you have 2 winners! I am in the Dallas area also, where do you shoot at? Winchester on NW Highway by the river will not alow FMJ.Have you shot at Quail Creek off 35W and 1171 north of Alliance Airport? They used to alow FMJ years ago. Thanks, Market Hall was a good show even with the rain (I was broke). RM

DougW
April 15, 2002, 11:03
ratas, thanks for the info! I was shooting off the bench, and usually will place my hand on the frot stock and rest on my hand. I feel more in controll. I also didn't tell you that I re-checked the headspace on both and both are perfect. I got lucky I think!

Michael64, thanks, and good to meet you to! The show appeard pretty good, with a lot of traffic. I am glad I met DeanP also, and sledghammer, so I can find parts locally for my next frankenfal.

Chainsaw, I shoot mostly at Gibson's Outpost in Mesquite(?) area (south off Hwy80 on Lawson road). I have also shot in McKinney, or should I say at the public range in McKinney. Both allow milsurp/FMJ, so cost is kept low. I don't really care for Winchester, as there are not that many friendly people around there, plus you have to jump through hoops to shoot there. Pistol there is ok, as I am close to that range. The last time I was at Quail Creek they too did not allow FMJ. I have not shot in Denton or Garland ranges. Good Luck!