90 VLD Sanity Check

[Jeff Porter]

I have a Panda action rifle that I have recently taken off the .308 barrel and installed a 30" Bartlein 1:7 with what is stamped on the side is 223 FTR chamber. I did not buy this barrel new and do not know what reamer that is.

I want to shoot Berger 90 VLD and measuring to touch I get 2.083" BTO with my tools for that bullet. This puts the shank in the neck and the boat tail just into the top of the shoulder. (It is interesting to me that the 85.5 and the 80.5 have similar BTO and bullet fit in the case.)

Measuring the same bullet in this chamber and in a Kreiger with a Wylde chamber I get 0.120" shorter touch measurement in the Wylde.

Am I correct in deducing that this 223 FTR chamber has about 0.185" freebore? OAL on a bullet at touch is 2.705"

I am preparing to work up a load with H48956 or IMR 8208. I have fired some 88 ELD M loaded with both powders to get some zeros on the iron sights and the scope. I did Varget too but velo was just a bit short of what I was wanting to see. I did a quick and dirty two shot information gathering with the 88's set at 0.020" off touch and was able to get up to 25.0 gr. of each before seeing the slightest sign of pressure on the 205MAR primers. Data shows I should be able to get my desired 2850 with about 24.4 gr of either powder. I use H4895 in my 6 BRA and am going to start with the 8208 to save my inventory.

Anyone used 8208 with these before? I have been shooting it with 77's & 80's for years with no issues but have heard it is spiky at the top with these heavies.

Looking through the archives I see I should tag @Ned Ludd as he seems to be the guru of all things 90 VLD and 223 FTR

 

[Jeff Porter]

Image of the 88ELDM and velos for two shot test. Orange plaster. 80.5s on black.

 

[urbanrifleman]

Am I correct in deducing that this 223 FTR chamber has about 0.185" freebore?

yup.

 

[urbanrifleman]

Those 8208 88 ELDM loads have to be overpressure.

 

[Jeff Porter]

One would think but no hard bolt lift no clickers primers still round up to 25.0.

 

[perazziguy]

I would second that about @Ned Ludd . I enjoy reading about his findings with the 223. I don't even have one...

 

[urbanrifleman]

One would think but no hard bolt lift no clickers primers still round up to 25.0.

That is over the Varget load data for 80 grains, much less 88 gr. Varget is at least one grain faster than Varget.

I shoot AR COMP which essentially the same speed and I topped out at 24 grains with 88s and I have a 230 fb.

 

[CJ6]

Pressure is a combination of barrel, bullet, powder (lot) primer (lot) and case (lot). Books will get you a starting point and not much else, the same with the "programs". The rifle and load combinations will tell you what is and isn't right.....Just my 2 cents.

 

[10XSHOOTER]

Did I read right? He took off a .308 barrel and installed a .223. Never said anything bout changing bolt?????

 

[Ned Ludd]

I think the fired targets indicate that all appropriate considerations were properly addressed.

 

[jelenko]

Yeah, Jeff knows the difference.

 

[1911mag]

I have not used 8208 for 90’s before. I initially used Varget, then N150, now running H4895. Going to change back to save on H4895. Honestly the 85.5 has been easier to tune and more forgiving.

 

[Jeff Porter]

Did I read right? He took off a .308 barrel and installed a .223. Never said anything bout changing bolt?????

I guess that didn’t go without saying …. Yes Kelbley Panda big bore action with two bolts. 10 minute job to switch barrels and bolt face selection too.

 

[Jeff Porter]

I got to do some work at 100 yards with 8208 and H4895 loaded 0.020" off of touch using a beat up crappy Caldwell front rest and a Magnetospeed hanging off the muzzle.

I was looking to do OCW but POI shifts at 100 were not very pronounced. Shooting at a grid with 0.1mil squares all groups fell into a 3/4" block of four squares. my POI notation is where in the square the group centered. I know we are not looking for groups initially in OCW but I was not too upset with the results. Particularly for the H4895.

As already indicated by others work, 2830-2860 fps range appears to be a sweet spot. H4895 didn't seem to care what the charge or velocity was, it just plunked 3 bullets into a 0.4" hole. 8208 produced some stellar velocities but I started seeing the primers start to flatten at 2900fps.

I will focus on the 24.0-24.2 region of H4895 and tweak seating depth to determine if these are going to be tolerant of throat changes as it erodes back and see if I can shake loose and stretch it out to at least 500 yards before I load up a bunch of these.

H4895





8208

 

[Jeff Porter]

Here is the target I was using with 0.1 mil grids.

 

[Jeff Porter]

@Ned Ludd That has been my experience with the 75 VLD's too. I have had luck finding the window and seating to the long side and let the throat erode through the window without needing to chase the lands again for quite a few matches. I am sling shooting, not BR or even F-class so my tolerance of a 0.4" group is pretty high. If I can keep it in the 0.2 to 0.5 range It will be plenty precise for my work. The rest is up to me.

 

[DR_2297]

My BTO with MY comparator is 1.945 to touch. That’s a 90 in the Manson T15 Fullbore chamber (0.200 total freebore). OAL about 2.635. Been using N135 at about 2830 fps. Second and Last match of the Perry 3x600 were 200-11X and 200-14X. Shot a 197-8X @1k this morning. All 3 9s were caused by me. Front half was 99-7X. It’ll shoot.

 

[Jeff Porter]

So I backed down to 24.1 H4895 to get 2860 and did a jump test. From 8 in to 35 off at 200 yards. None of the jumps were horrible with most groups right at a hair over 1” at 200. When I got out to 0.020” off and continuing out to 0.035 off the three shot groups tightened up and the 0.030 and the 0.035” jump load were just under 0.3 moa.
Below is the 0.030” jump group.



I also loaded at Ned’s 23.9. Load at 0.020” off and shot them in a string of 10 shots from the ground sling up. Even though they are 30 fps slower at 2830 fps, at 200 they grouped with the 24.1 within my hold for a 6x clean.

I am ready to take this load out to 600 and beyond now. Thank you all for the input.

 

[1911mag]

Bring it to IL state

 

[iukamedic]

Jeff. I hope I didn’t bring that bug to your ear. Lol
I’ve been working on my new set up a little too.

Edit. I just realized the started over a month ago. Sorry