SmallCaliberCentral

Sunday afternoon the 17th I had some really encouraging results with my first batch of 34gr Dogtowns using Ramshot TAC powder. This afternoon I went back out with a more refined batch. Sundays results told me the best loads should be charged somewhere from 27.5 to 27.8 grains. Today I had 40 rounds weighed on an RCBS Chargemaster Combo dispenser/scale. (10)@27.5, (10)@27.6, (10)@27.7, and (10)@27.8.

Thursday May 21, 2009
Dtech .204 Ruger AR-15 1:10 twist Shilen w/muzzle brake.
Millett 4-16x, @16x, 100 yards
34gr Dogtown bullet
Ramshot TAC powder
Rem 7 1.2 Primer
Winchester Once-Fired, Full Length Sized Brass (Sunday's loads used NEW Win Brass, prepped of course)
2.244" COAL
Unknown velocity. Too dark/overcast for chrono.
68F / 70% Humidity, Wind calm, dry.

* Something I must point out: I did not clean this rifle after the ~80 shots fired 5 days ago. I refrained from cleaning because I thought I might be able to find a load that worked well dirty. I'm beginning to think I may have never seen this barrel shoot any different, ever, whether it's clean or dirty. I could not tell today whether accuracy came and went because of being dirty, being hot, whatever. I'm left a bit confused, because the 3rd set of 5 rounds (27.5) looked to me like I expected. Pretty tight for a .135BC bullet. The 4th-8th groups did not yield any particularly good accuracy. The 9th and especially 10th group surprised me. They were the 27.7 and 27.8gr charges, and the barrel was definitely getting close to HOT at that point.

* I began this round of testing shooting ten rounds I had left from Sunday that I didn't think were worth shooting, just to warm the barrel up. I want a prairie dog load that will be accurate when warm/hot.

Sorry for the wide graphic. It just seemed the most clear way to present the info.
Please give me your analysis, because unless I'm just not very steady on the bench, I'm not seeing any conistent reaults. it looks like 27.5 shoots best when it's relatively cool, then 27.7 and 27.8 get better the warmer it gets. So what do I settle on using? The 27.6 shot best Sunday. ???



Group 6 was only 3 shots. I couldn't resist killing something that wandered onto the range. Had to make sure it was dead with a 2nd shot.

Is it normal to see my heartbeat in the scope at 16x@100yds? Sometimes when the crosshairs bob left and right it drives me nuts. I've heard to turn the power down, but really, the movement doesn't go away at lower power. You just don't see it. Not sure why that should result in more accuracy, but it's something that drives me nuts thinking about.

This felt like a bad day at the range. Poor results. Not sure where to go from here.

I hope you guys can read something constructive on these, besides needing to move my scope 2 clicks right.

Shoot 5/5/5/5 of 27.5/.6/.7/.8 again....but with a black and white target. Bet your groups come down a bit.

What power is your scope on? If a variable, limit the power to 10x or 12x as well.

Clean the barrel, use a carbon solvent like BoreTech's C4 after cleaning with copper solvent.

Take the best load (RD3) and set the OAL to 2.260" or factory length. Load enough to give a few rounds of fouling shots.

My .204 Ruger didn't shoot up to its potential until I seated the bullets well off the lands at the 2.260" depth. Experiment with seating depth - closer to the lands isn't always the most accurate. I would say your results looked like mine until I seated deeper.

Otherwise you are doing everything already - especially using the Remington 7 1/2 primer with TAC. My little old skinny barrel Remington 788 in .223 Remington really shoots TAC - it's a .5" rifle with TAC (27.8 grains) and the 36 grain Barnes Varmint Grenade. I plan to try TAC in the .204 Ruger next, it runs through a measure with almost perfect consistency, is accurate and it would be nice to have one powder for both cartridges. I may try it in the 6mm PPC - with Varmint Grenades due to its loading density.

I do my range work with 24X settings on my scopes, but seldom go above 14 power (usually 10X) when shooting ground squirrels. Heartbeat motion in the scope is normal - especially for me - my heart is big enough for a pony. Keep both eyes open, and relax.

Wrangler John, this is an AR, so I have to develop a load that works at a length that will fit in the magazine. I found 2.244 COAL to be a good length for feeding, as when I loaded at 2.251, I would sometimes get bullets that went long, and I think they got hung up feeding into the chamber. 2.244 keeps even the long ones under 2.250, so ? If I was to change anything with these 34gr Dogtown bullets, it may be to go even shorter. I've seen people post loading them shorter.

OK, I cleaned WELL Friday night, which brought up another possibility in these inconsistent groups. I cleaned for carbon, then for copper, the whole soaking and scrubbing routine, until I got clean patches. I also cleaned the chamber and locking lugs, bolt carrier group, and upper receiver until they were clean and dry. With an AR you have to re-oil everything, or the steel bolt carrier will wear your upper receiver. The bolt likes to be run wet too. There's holes where it needs a drop of oil.

After doing my cleaning everything dry then re-oiling routine (Breakfree CLP), I cycled the action about 20 times to distribute the oil across those moving parts. I then looked in the chamber and saw the locking lugs had a thick coat of oil on them. This made me think I must be using WAY too much oil. Enough that it gets in the barrel? It didn't look like the oil was in the chamber, but when a bullet feeds into the AR-15 chamber, the bullet tip hits feed ramps cut into the locking lugs to direct it toward the chamber if it's coming in off center. If the bullet pick up oil in this process, taking it into the barrel, this could make for some very inconsistent velocities.

So that's my suspicion. My rifle was jamming last fall, at one point this winter it felt like things were binding, like pulling the charging handle became more difficult. Ater that I tried a heavier coat of oil, and it ran perfectly. Haven't had a jam since. Now I think I need to find the right balance, and accept that I'm just going to have to break the bolt carrier group down to parts more often and clean more, oil less. Friday night I tried less oil, and made sure the feed ramps, bolt face, etc, stayed dry when cycling the action.

My other suspicion on these groups is that it's my poor shooting technique.

Yesterday, I took loads of 27.5gr and 27.8gr out at 100 yards. I shot 7 shots of a 27.6gr load to warm up the gun and season the barrel a bit. I then shot (5) of 27.5, (5) of 27.8, (5) of 27.5, and another (5) of 27.8. On the first group of 27.5, I remember seeing my heartbeat in the scope, and decided I'd try letting go of the gun as much as possible. This worked for the heartbeat, but since the bench wasn't level, I think the gun jumping inconsistently on ignition threw the group off. I shot two very poor groups that way, then on the 2nd round with each charge, I decided I was going to try a firm grip pushed into my shoulder, leaning forward into the bipod, pulling the whole rifle down onto the bench. I did get some heartbeat motion back in the scope, but this produced 2 4-shot groups of about .4, each having 1 flyer out to an inch.

So I'm still not left with anything conclusive. I guess I do know now that using a bipod/rear monopod combo, I need to hold on tight for best accuracy. Next outing I'll be trying even less oil too.

I'll report back here.

BabaO'riley, I've found that if I disassemble everything for cleaning in my ARs and after I get them clean, I place one drop of oil on each part, smear it around with my finger, and then wipe them down where there is just a slight film of lubricant on the part, I have no problems.

The only part that is fairly wet is where the bolt slides into the carrier... I picked up a lubricant from Brownell's called "Friction Defense" (their concoction) and it's worked great for the last three years...

When I'm working up loads, I use a Lead Sled and strap it to the shooting bench, and tie the rifle to the sled.... It helps reduce the 'human' factor from the equation and all I'm touching is the trigger...almost like using a Ransom Rest with a handgun...

Then when I get the best load results I can, any accuracy problems I know are mine and I can work them out..but I want to know that my loads are the best I can achieve..

OldTurtle wrote:When I'm working up loads, I use a Lead Sled

I hear differing views on this. When I started reloading I wanted to get a lead sled myself. I figured it would take the human error factor out of the equation. Then I read several times that when doing load development to shoot it as you plan to on the bench or in the field, because the load may not give the same result if vibrations are different when strapped down vs off a bipod/bag/etc... Not to discount your advice. I know that's what the lead sled is for, so it must work for MANY of people.

I'll check out that oil. I'm betting I'm just going to have to clean more and oil less. When it started to bind up it was probably more dirty than lack of oil. I would guess the action not running smoothly can severely effect velocities in gas gun! I'll get this thing figured out sooner or later, and let you know how things go here...

Baba Oriley:

Duh! I misread your post - sorry. I ain't got any recommendations for the AR platform. My friend in Oregon picked up a Les Baer AR .204 Ruger Super Varmint and swears it shoots .5", so they must be capable of fine accuracy. The only AR I worked with was a Colt version back in 1965 - and I seem to recall it was fairly accurate also - around 1".

Say, didn't the original M-16 have a bit of difficulty in Nam with oil, humidity and the gas system jamming up? IIRC that led to the development of the forward assist plunger to force the bolt closed. It also led to Dri-Slide lube being privately purchased and shipped to the troops by friends and relatives. They still make Dri-Slide for firearms, maybe that would work better than oil that migrates. http://www.uniquetek.com/site/696296/product/T1247 A dry Molybdenum Disulfide and Graphite lube with rust inhibitors in a evaporative solvent carrier, may give better consistency than a wet lube. The high pressure resistant moly film should protect the upper just as well, if not better than a synthetic oil based product. Molybdenum Disulfide will plate steel, and doesn't gather dirt or residue. Dri-Slide got good reviews in Iraq too. Just a thought.

BabaOriley--Personally, I think OldTurtle gave you some good advice about using the Lead Sled when developing the loads to take the "human factor" out of the equation. Once you find a load or loads that work great, then you take the firearm out of the Lead Sled and shoot it in the manner you will use it in the field, i.e. off a bipod front, off-hand, whatever your shooting style, to see if that load or those loads are still giving you itty bitty groups.