.308, RL-17, and Hornady 178 HPBT in a gas gun

[CrawDad338]

I found a nice little combo at the range today. It's my understanding that Hornady Superfomance 178 HPBT loads have pressure related problems in gas guns. That wouldn't surprise me given their soft brass. I wanted to post this load data in case someone was looking for an alternative. I'm not saying this will work in all gas guns but it sure worked well in mine, no pressure signs here. I'm no sharpshooter BTW.

Load details: Virgin Winchester Brass, 49.5gr of RL-17,Hornady 178 HPBT, 2703fps avg velocity, 14fps ES, 6fps SD (22'' barrel). I wanted to try 50gr but the load was already compressed a good bit. I loaded these to a COAL of 2.810 +/- .010 due to the imperfections in the meplats , the projectiles avg 1.345'' long. As always ladder your way up to this charge.

The gun was a DPMS LR-308L, but I added a Magpul PRS stock and swapped the barrel for a 22'' Fulton Armory 12 twist w/ Cooley brake.

I'm really pleased with these bullets for 25 bucks per hundred. According to Bryan Litz they have a G7 BC of .257; 2,700fps keeps them supersonic for 1,120 yards down here in the Bayou State.

100 yard target: Lowest powder charge on the right(45gr)only 2,550fps.worst group with this combo, guessing bullet rpm was lacking with my 12 twist. 46gr in the middle, 47gr on the left.

Best group 49.5gr RL-17, groups got progressively better as velocity increased.

 

[00bullitt]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

I'm mirroring the same results with Barnes 175gr. Match Burners and 49gr. of RL17. The gun operates beautifully with a very consistent ejection pattern and easily holds 1/2moa to 600 yards. I'm loading to 2.84" so that the rounds will fit in the metal mag of my OBR. PMAGS require a much shorter OAL of 2.79. The RL17 load is so compressed I cannot load any shorter for consistency sake. I am getting 2610 out of my 18" OBR.

RL17 has become my favorite powder. I use it in about 7 different cartridges. All produce fantastic velocity with great accuracy.

 

[CrawDad338]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 00bullitt</div><div class="ubbcode-body"> The RL17 load is so compressed I cannot load any shorter for consistency sake. I am getting 2610 out of my 18" OBR.

RL17 has become my favorite powder. I use it in about 7 different cartridges. All produce fantastic velocity with great accuracy. </div></div>

I've only been reloading for a couple months and I was curious about compressed loads. How do you know if they are too compressed? 49.5gr is just above the bottom neck line and after I seat the bullets to 2.81'' the bottom of the bullet is .255' below the neckline. The powder isn't crunching or anything but I'm certainly nervous to try more.

 

[00bullitt]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

Too compressed is when you cannot obtain consistent seating depth due to push back or if you are crunching powder to create inconsistent velocities.

In the case of RL17, you cannot get enough in the .308 case to create a pressure issue when driving 175's.

 

[recarga]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

CRAWDAD 338 , Thanks for the info , I'm trying re17 on 6.5-55 and I'm getting good results on it.

I'm happy with results from VIHT N-140 for my Armalite AR10 but I have not reach the speed that I'm looking for 500 yards , and RE 17 sounds like a good candidate for the job.

Q. Have you done any CRIMP on your loads ( lee factory CRIMP ) just asking because my AR seems to like it on the A-max and bergers.

 

[CrawDad338]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: recarga</div><div class="ubbcode-body">CRAWDAD 338 , Thanks for the info , I'm trying re17 on 6.5-55 and I'm getting good results on it.

I'm happy with results from VIHT N-140 for my Armalite AR10 but I have not reach the speed that I'm looking for 500 yards , and RE 17 sounds like a good candidate for the job.

Q. Have you done any CRIMP on your loads ( lee factory CRIMP ) just asking because my AR seems to like it on the A-max and bergers. </div></div>

You're welcome. No, I need to learn how to crimp next. I'm still load developing so I figured it wouldn't hurt to leave out another variable and have uniform neck tension. Are you saying that your gun actually shoots better with a crimp on the projectiles? I hear crimping is essential in gas guns. I filled up a 20 round mag of non crimped, shot 5 rounds, measured the 15 remaining rounds and my COAL still matched what I had written on the cases, shot 5 more rounds measured the remaining 10 and the COAL didn't budge. Have you ever seen problems with the bullets moving around non-crimped in a gas gun?

 

[00bullitt]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

So long as you use a .002-.003 neck tension, bullet shift in the magazine should not be an issue. Where you will get setback is feeding in to the chamber from the magazine.

Non bushing type dies usually provide at minimum .003 neck tension. They tend to err on the tighter side due to variations in neck wall thickness of different brass manufacturers.

With load density as with RL17, setback will not be an issue as the powder in the case will restrict such.

 

[CrawDad338]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 00bullitt</div><div class="ubbcode-body">So long as you use a .002-.003 neck tension, bullet shift in the magazine should not be an issue. Where you will get setback is feeding in to the chamber from the magazine.

Non bushing type dies usually provide at minimum .003 neck tension.

With load density as with RL17, setback will not be an issue as the powder in the case will restrict such.</div></div>


That's good to know, Thanks! My Redding seating die (A Series)has a crimp feature built in if I screw the die body down more but it sounds like I may not need it. Every now and then I will measure rounds at the bottom of the magazine before and after to make sure they are not shifting.

 

[recarga]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CrawDad338</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: recarga</div><div class="ubbcode-body">CRAWDAD 338 , Thanks for the info , I'm trying re17 on 6.5-55 and I'm getting good results on it.

I'm happy with results from VIHT N-140 for my Armalite AR10 but I have not reach the speed that I'm looking for 500 yards , and RE 17 sounds like a good candidate for the job.

Q. Have you done any CRIMP on your loads ( lee factory CRIMP ) just asking because my AR seems to like it on the A-max and bergers. </div></div>

Your welcome. No, I need to learn how to crimp next. I'm still load developing so I figured it wouldn't hurt to leave out another variable and have uniform neck tension. Are you saying that your gun actually shoots better with a crimp on the projectiles? I hear crimping is essential in gas guns. I filled up a 20 round mag of non crimped, shot 5 rounds, measured the 15 remaining rounds and my COAL still matched what I had written on the cases, shot 5 more rounds measured the remaining 10 and the COAL didn't budge. Have you ever seen problems with the bullets moving around non-crimped in a gas gun?

</div></div>

I only use the lee factory CRIMP to give that extra pressure for Berger vld since they are hungry for the lands and they don't like that jump.

This is my starting load for the 155 vld you can see the BIG difference from non CRIMP and CRIMP.
It's only a 3 shot group since I was testing only.

 

[CrawDad338]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: recarga</div><div class="ubbcode-body">

I only use the lee factory CRIMP to give that extra pressure for Berger vld since they are hungry for the lands and they don't like that jump.

This is my starting load for the 155 vld you can see the BIG difference from non CRIMP and CRIMP.
It's only a 3 shot group since I was testing only.

</div></div>

Very interesting, I had no idea a "Lee factory crimp die" could improve accuracy. I just thought of a crimp as one more thing to mess up. I just looked up the price on the dies, definitely worth a try for such a small investment. Thanks for the lead.

 

[recarga]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

Like the gentleman above had said most of your dies (not bushing types) will give enough neck tension ( most if not all to mush ) for gas rifles.

If you decide on the LFC die , don't follow the instructions as it will destroy the top of the neck , just a little ring around the top of the neck will do.

And by the way great groupings you Got there , and is only a stinking gas gun ha.

 

[LineofDeparture]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

Crawdad.... if you want to try the Lee Factory Crimp Die before you go spend 20 bucks or so on it.. you are welcome to use mine....You know where i live

 

[mkollman74]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

Any concerns with temp. sensitivity with the R-17?

 

[CrawDad338]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mkollman74</div><div class="ubbcode-body">Any concerns with temp. sensitivity with the R-17?</div></div>

Not so much living near the Gulf of Mexico it's pretty much hot as hell all the time, but I'm looking forward to a cold day to see what my chrono reads with this powder.

 

[CrawDad338]

Re: .308, RL-17, and Hornady 178 HPBT in a gas gun

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 00bullitt</div><div class="ubbcode-body"> The RL17 load is so compressed I cannot load any shorter for consistency sake. I am getting 2610 out of my 18" OBR.

</div></div>

00bullitt, Using a drop tube I was able to fit 49.5 gr of RL-17 without much if any compression with the Hornady 178 HPBT and a 2.820 COAL. I could actually hear some shake in a few cases...

Powder level with just the funnel on the left, with the drop tube/extension on the right.

 

[Mumbles]

So, any new thoughts on this combo a year later? Still shooting it? Any long term negative or positive effects you've noticed? I've been scouring the entire internet for about a week now, but this is pretty much the only instance I've been able to find of someone using 178 HPBT/RE17 in a gas-gun.

I've started to work on a load myself. It'll be out of an LMT MWS 16" CL though. I don't own or know anyone with a chrono, so it's gonna be pure guesswork on the MV starting out. Should get a good idea once I start shooting at longer distances and plugging in the actual drop.

 

[JGorski]

Crawdad.... if you want to try the Lee Factory Crimp Die before you go spend 20 bucks or so on it.. you are welcome to use mine....You know where i live

Nobody needs that silly thing, crimping is totally uncalled for.