AR-15 in 17 Remington

[Jkoch]

Put together a Shilen Ar15 barrel in 17rem.
I didn’t see in any of the reviews about having issues with action stripping new rounds, ejecting and locking back on last round.
Had to go with a lighter BCG, 9 rings off buffer spring. Adjustable gas Block wide open.
Using IMR 4198 and 20/25 grain bullets.
If using cfe223/tac/varget ect. It would produce more gas and operate things with a reduced springco buffer spring and lock back.

Aware that IMR 4198 does not produce lots of gas pressure like the slower burning powders. I wanted to run this using 4198 so went the rings off the buffer spring.

 

[squirrelsplitter]

jkoch,
Welcome to the forum.
Can you further explain the issues you are having?
I have a 17 Rem upper with the same barrel that I have had no issues with.

 

[GLShooter]

Sounds like the port is too small. I'm running a Black Hole 17 Rem with standard BCG and spings. No issues at all. The same thing goes with a 17-233.

Greg

 

[Brownie36]

Me too Greg. Got your set up, no problems. Taking it to Texas in May for PD’s will give it an extreme work out then. Using multiple powders from the load data books and all are working great but not using 4198.

 

[Jkoch]

(Port too small). That is what I was looking at as well. It looked similar to a 223/wylde barrel port size yet didn’t have a hole gauge so no official measure. The gas block fits tight. It is a superlative gas block that bleeds off air but should not effect anything if wide open (it is now)
I didn’t want to send the barrel back to shilen. Just drilling a larger hole ? It appears there is open space closer to the chamber, and drilling a larger hole in the same hole, may not give it ideal placement?

 

[Jkoch]

I checked the gas port hole to gas block line up and it was dead on. Will take some pictures. I think some of the issues were related to the single shot clip conversion that holds it open on last shot, bout when on the range I remember full house hot loads with cfe 223, varget, not holding bolt open even with a regular clip. Will have to test more to confirm.
thank you for the responses guys!

 

[GLShooter]

I'd drill it about 0.004 to start and test. I would want it running with full springs and bcg but that's your call if you want a dedicated lower no need to change.

I run over 30 various uppers from 17-223 to 458 SOCOM and all are spring normally with standard buffers. They all run well. 95% have adjustable blocks. About 20 of them are wildcats done on the 6.5 and 6.8.

Keep us posted.

Greg

 

[dfrosch]

I'd drill it about 0.004 to start and test. I would want it running with full springs and bcg but that's your call if you want a dedicated lower no need to change.

I run over 30 various uppers from 17-223 to 458 SOCOM and all are spring normally with standard buffers. They all run well. 95% have adjustable blocks. About 20 of them are wildcats done on the 6.5 and 6.8.

Keep us posted.

Greg

This.

To keep the drill bit from hitting the far side, wrap the bit with masking tape at the proper depth. If you can find a small enough wooden dowel, put it in the bore too.

A tiny bit of blue Loctite around the barrel port, but not in it, will ensure that there's no leakage around the gas block.

 

[Coyotefurharvester]

Built mine back in 2003-4, Shilen barrel and bolt combo. Everything is standard rifle parts, I did alter a plain jane gb so I can shut off when shooting off bench. Mine is a 1/10 twist so I only shoot 25gr hp.

 

[SVT_Tactical]

Opening up the gas port cant really hurt much especially with an adjustable gas block. You can always cut it back down using the block but it was under gassed based on your description. I don't like cutting coils because I've found on systems where folks have done this they loose the reliability after a little bit of shooting and its getting dirty.

 

[Jkoch]

Hey thanks for all the replies guys that’s a genius deal to use a fowl down the barrel if you want to drill the gas port out! l what a great idea..
so here’s the most recent:
I came to the conclusion that the IMR 4198 will not produce enough gas to run the AR system reliably unless you start cutting coils on the spring..you’re right reliability is an issue.
After I shot a bunch of CFE 223 today, it worked great!
I’m going to use that powder because it produces similar to benchmark velocities and even goes higher without getting the very high pressures.
I was easily able to do 4200 ft./s with 20 grn pills and 4000 ft./s with 25 grainers. I used a reduced spring from Sprinco, left the same BCG which was lightened but I’m sure I’d probably run with a regular one as well but everything function great no issue. Very light recoil, Cases were ejecting 3 to 4 o’clock, (using the adjustable gas block)
I could’ve used the regular spring if I wanted to but it ran so well the way it was I left it

in conclusion the issue was the IMR 4198 powder just not supplying enough gas to run the system properly
I am a little bummed because it was one of the more accurate powders that people have talked about it also is the most accurate for both 20 and 25 grain bullets in the Lymans reloading manual. I could run it as a single shot on the bench if I really wanted to, but not worth the hassle.

I will be able to use IMR 4198 powder in a 17 hornet bolt action CZ and those velocities are right up there to max unlike in the Remington 17 they were about 200 ft./s slower.

So all honesty I actually won out as I gained 200 feet per second on velocity and the gun is functioning as it should.

and as the saying goes threads are useless unless it has pictures I’ll show you some casings that were shot with the IMR 4198 and the CFE 223’s

25-25.2 grains CFE223
25grain hornady HP
25grain Berger HP Varmint
Primer hole looks like it is higher pressures in the Hornady 25 grn hollowpoint .



26-26.4 grns CFE223
20grain V-max, Varmageddon Hp
4,200 FPS

It looks like it’s about one grain difference when you use 20 or 25 gn bullets. to get factory velocities w/o going over pressure.
The reloading manuals seem to concur with this.

Green RCBS CASE=all CFE223 powder
25grn bullets (top left row of five)

20grn on right side top five
The top row were the highest charge and turned out to what I will load to now.

note: one primer showed a bowed primer pocket.
This was with 25grn pill and 25.4 powder charge.
perhaps I will have to lower my charge more but 25.2 didn’t show these pressure signals but .2 grain may push it over with the smaller calibers I have to look into it further.
It may also be the depths of the bullet as well as this was with the 25 grn bullets

 

[fkimble@charter.net]

Two things from your pics:
First, the pic with the loaded round bullet up. It appears there is a lot of jacket scraping the the mouth of the case. Are you chamfering your case mouths?

Second, the case with the raised area around the firing pin indentation. This can be from extremely short headspace with the brass or extremely low loads, especially combined with an over sized firing pin hole in the bolt face. May want to check your brass resizing.

Frank

 

[Coyotefurharvester]

I reduce charge loads when I use LC brass, as compared to factory Remington brass. It may take multiple firings of the LC to fully form.

 

[Jkoch]

Thanks for all the replies and the great ideas Powder I settled on;
CFE223
25grain in 25pill= too hot 4000-4150fps
26.2grain 20 gr pill= too hot= 4,200-4,400 FPS
The. Variance is caused by mixed case heads and different bullet manufacturers from Hornady to Nosler to Berger.

trying 24.5grain for 25grain pills
25.7 grain for 20 grain pills.

finding that these over bore tiny calibers are VERY sensitive to changes in powder charges.

to throw more ? To the wind I will test neck tension and lands to olgive space and how it effects pressures.. as the pulled bullets = did not resize the necks and some did and marked accordingly...

Hoping it does NOT effect anything (the neck tension part) I think it is well known about bullet-to-lands measurement and having bullet lose to lands increases preasures.... just not sure how much.

Also.. I was able to place stock Ar15 spring back in the buffer tube, as cfe223 provides plenty of gas to run the action.

now to write up about how the “snake bitten” case causes premature case neck holes or cracks when sizing down and or wildcats from the 223 /5.56 once fired range brass. Note the nice see through crack where there is a seemingly innocent lug scrape -aka “snake bite”

 

[Jkoch]

Two things from your pics:
First, the pic with the loaded round bullet up. It appears there is a lot of jacket scraping the the mouth of the case. Are you chamfering your case mouths?

Second, the case with the raised area around the firing pin indentation. This can be from extremely short headspace with the brass or extremely low loads, especially combined with an over sized firing pin hole in the bolt face. May want to check your brass resizing.

Frank

Thank you Frank I do know what you’re talking about when you get to under loads it’s happened with my 17 hornet.. hard to say. that may have been off the IMR 4198 powder maybe I did get a light charge with that powder it doesn’t flow very well it’s like pencil sticks!

I’ll try and keep it short but I had shaken my new rounds that I am trying today. One of them didn’t have the same sound as the other ones (les sound =more powder or less room in case) so I pulled it and weighed it and it was off by 0.2 grains. so instead of 24.5 I it was 24.7gr
These were all done with single stage powder thrower and weighed almost all of them on the digital scale. Go figure. The mechanical scales seem to be the most accurate. These digital ones if you don’t have it perfectly flat or centered or a little off in the powder cup it weighs differently. Not so in the mechanical ones.

I have noticed when you get such high pressures that eventually the primer metal will start to flow into the primer hole I think that was the only one like that where it actually flattened out just kind of bizarre.
there’s a picture below: got enough pressure to have the case head flow into the ejector hole!
( marked with marker and then rubbed it on a flat surface and the shiny spot is where it was raised)

those cases were used a couple different times without resizing I had to pull bullets because I was changing different powders and such so I may have gotten a little beat up! (Caused the brass to scrape bullets)

I wish that our RCBS made a nice bullet press like they have on their match series. It has a nice side cut where you drop a bullet in from the top. The 17 caliber are a pain in , well you get the picture, to place in the case and bring up to the die....gr

 

[Coyotefurharvester]

I used a small fine file to remove sharp edges on the ramps and barrel extension, this will eliminate/reduce case damage during chambering and extraction. I run my 24" Shilen at 3900 with 25gr hp for prairie dogs, raccoons and red fox. I usually run LC 556 brass formed to 17 rem, especially in the winter with snow as I don't want to lose factory 17 rem brass. Really no difference between 3900 and 4000 inside 300 yards. I run 10 rd aluminum mags. Some mags I have needed to adjust the lips, especially if you have dropped them. I size so no forward assist is needed, no bullet crimp. I did reduce the diameter on the expander to 0.168-9 for a little more neck tension.

 

[Jkoch]

It appears that the shillen Remington 17 barrels are cut with a very tight chamber
After reducing my loads too .5 g less there’s still quite hot and beating the brass up more than I want. 4200 with 20ge pills @25.7gr of cfe 223 and 3900-4000 FPS @24.5grns
warmed up 60° more than what I was shooting at the prior week. And FPS is similar despite the decrease in powder charge.
I am still a relatively new reloader when it comes to rifle rounds and high pressures

I am a bit bummed that the AR 10 in 22 Creedmoor does not put out the velocity that the bolt action rifles were. Went at it today, vrs the Ar15 -17rem velocities achieve very sim FPS as the bolt actions..

 

[Jkoch]

Too note: I have the bullets 0.005 the lands it would appear this effects pressure as well, by increasing it.

 

[Coyotefurharvester]

I don't /won't run AR loads into the lands, hunting or field loads start 0.020 off and tune away from the lands. Haven't found 17 cal bullets to be fussy about jump, charge weights yes.

 

[Jkoch]

I believe I settled on a charge of 24.2 gr of CFE 223. For 24gr hp hornady and Berger bullets. 25.2gr for all of the 20 grain pills.

Not worried too much about the seating depth, as this rifle has shot hole in hole at 50yrds. Move out to 100yrds as the 100yrd was in use last time out.

Will post picks of results..