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With my bolt dis assembled,I can easily close it on a new un sized case. The shoulder isn't an issue for me. I resize fired brass to 1.256"
I should be a little more descriptive. When I only neck up brass, it will chamber, just a little stiff. bringing the die down cleans up the shoulder and makes it easier to chamber, for me anyway. So not really needed, but that's what I do. It also doesn't hurt anything because like I said, the headspace on the newly formed brass ends up right where I want it.

Also went and run a couple pieces of brass just over the expander ball, not through the whole die. Still have donuts. Headspace is around 1.2570"-1.2575". Measuring the case mouth, they are at ~.2750". Measuring at the inner neck-shoulder junction, they are at ~.2735". Granted that's with calipers that are only accurate within .0005", but still.
 

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I'm wanting to get back to using the 110gr Accubond bullet. Is H322 a suitable powder? I have a bunch of it I would like to use.
 

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Discussion Starter #83 (Edited)
I'm wanting to get back to using the 110gr Accubond bullet. Is H322 a suitable powder? I have a bunch of it I would like to use.
The burn rate will be on the fast side and may not produce the fastest velocity but it can be used. start around 31gr and work up to maybe 33.
 

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The burn rate will be on the fast side and may not produce the fastest velocity but it can be used. start around 31gr and work up to maybe 33.
That's what I was looking for, thanks! I'll give it a try and see. CFE223 is working pretty good but it's too compressed for my liking.
 

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130 Hot Core

I found my go to load for the Speer 130 Hot Core.



Load data : 32.5 grains 8208 XBR, CCI 41 @2.260" COAL shot at 88*,1300' elevation. Chrono info to come.
Low round was cold bore, 4 rounds above it.
This showed no pressure signs in MY rifle. Work up your loads.
 

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A couple of questions, and maybe these are dumb questions, but here goes:

What’s the difference between 270AR and 270MSR?

Which magazines are used for the 270MSR?
 

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Discussion Starter #89
A couple of questions, and maybe these are dumb questions, but here goes:

What’s the difference between 270AR and 270MSR?

Which magazines are used for the 270MSR?
I use PRI 6.8 mags because they are stiffer and do not bulge.
The 270 MSR uses 6mm Dasher brass, a simple neck up. The 270AR is made from 6.5x47, 6.5 Creed or 308 brass, that means cutting it off and pushing the shoulder way back. The reason I made the 270MSR is it is easy, you don't have to fireform, trim or anything else.
 

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270msr gun skin

just finished putting my gun skin on the 270msr. a took a bit of time to do but I'm loving how it came out. looking forward to hunting with in a few weeks. I'll being using the 120mkz with h4895. I havent perfected the load yet but 34.5 grains was giving me 2850 fps. some slight swipes but primers looked fine.
 

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I've been trying to find the right load for 110gr AB's. I couldn't get CFE223 to group very well so I went back to H335 and found 37.5gr at 2.29COL has tightened the groups up very nicely and pressure signs look to be acceptable. I haven't checked velocity but expect somewhere close to 3000fps, hopefully. The same load produced over 3000fps in the 270AR with a 18" barrel, according to a post in the 270AR section. My 270MSR barrel is 20".
 

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so a bit of background on my setup: i've sleeved, pinned, and welded my side charging 270 msr barreled upper to make in legal for big game in my state. so, i'm running manually and suppressed with a 3-10 vx3. w/ sandman ti.

i ran cfe and rl 15 w/ the 95 ttsx. i also ran rl 15, cfe, and rl 17 w/ the 110 tsx. rl 15 produced two groups w/ the 110 tsx and one group w/ the 95 ttsx that were ~.5" 3 shot groups. all three groups had ragged hole groups going until the third round. in the pictured group i was loosing light and rushing- the third round was very likely me. no pics of the 110 tsx groups- i shoot at a public range. these were fired at 100yds.

i didn't have any luck with cfe or rl 17, though i might reshoot the upper loadings w/17 if i work out the extraction issues.

however, extraction was difficult with all charges including very conservative starting loads with rl 17. i'm not seeing traditional pressure signs on the brass or primers. i fired the first couple rounds unsuppressed w/ the same difficult extraction.

i use an rcbs turret press. running the msr die down to the lee shell holder resulted in brass that would not chamber. roughly, an additional 1/8 turn of the die resulted in brass that would chamber. this is where i sized all the brass that i fired. the sized brass produced a bit of a ring at the base of the neck. i use imperial sizing wax. all fired brass had two lines on the necks - unsure why? feed ramps? additionally, i received my barrel with the incorrect extension installed. i sent it back for the proper extension.

what are the most likely causes of my extraction issue? sizing brass?

first pic ...fired case, loaded rounds, prepped brass.
2nd pic...marks on the necks of fired cases
3rd pic...prepped brass...note the ring at the base of the neck. the light ring down on the case body is a result of my frankford trimmer.
4th pic...group w/ 33.5 gr rl 15 and the 95 ttsx...i didn't load any beyond 33.5gr w/ the 95 ttsx. very similar groups produced with the 110 tsx and rl 15...these were shot with 31.5 and 32 gr of rl 15. 32.5 gr was producing a good group with the 110 as well but i had a bad primer in the 3rd round so the group was incomplete. w/ the issue i'm having i haven't been back out w/ warmer loads. but rl 15 looks promising at least so far as accuracy with my rifle.
 

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Discussion Starter #94
additional pics.

fired case heads and rifle.
Reason for extraction problems? You are doing it manually. There is not a cam to pull the cartridge from the chamber like on a bolt gun.

2 lines on the necks? extract the round slowly and watch what happens through the port door. See how the ejector button pushes the round to the right to make it flip out the port door? Notice when the neck clears the breech the ejector slams the neck into the square extension lugs and then drags them across?
 

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well, ****. now i feel like an ass.

any guess where i'm at velocity wise w/ 32 gr rl15 and the 110 tsx? and 33.5 rl15 w/ the 95 ttsx? if i'm sacrificing too much velocity, this rifle will soon be a repeater.
 

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Discussion Starter #96
well, ****. now i feel like an ass.

any guess where i'm at velocity wise w/ 32 gr rl15 and the 110 tsx? and 33.5 rl15 w/ the 95 ttsx? if i'm sacrificing too much velocity, this rifle will soon be a repeater.
Maybe 2700
 

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i wouldn't consider this in any other situation, given it would increase bolt thrust. but if i used a chronograph and stayed below a certain velocity and pressure, say 2800 fps and its corresponding pressure (or whatever the magic number might be), could i apply a bit of imperial sizing wax to the cartridges to ease extraction? or would this be unsafe and NFG like i suspect? hell, i'm not even sure this would help extraction in my situation.

would a 7.62x39 16" 8 twist barrel make a better candidate for a straight pull upper with its tapered case and lower pressures? i could have hawk make me some thin walled bullets.

a better solution would be to use an upper with a gas system, paired with a lower that cannot hold a second round. however, i doubt the game commission will find this acceptable if the upper and lower can separate. perhaps not even then. i'll call the man to inquire.

*** i recognize that most reading this view a straight pull upper as a wasted rifle. i have rifles that perform as they were intended. most animals i hunt are taken with a bow or flintlock up close. so this project is just for fun and because i can.
 

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Do not apply any type of lube to the loaded ammo as it will increase bolt thrust as you suspect. This is also the same reason you want a dry chamber, the brass NEEDS to grip the chamber walls momentarily for proper operation.
 

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Discussion Starter #99
i wouldn't consider this in any other situation, given it would increase bolt thrust. but if i used a chronograph and stayed below a certain velocity and pressure, say 2800 fps and its corresponding pressure (or whatever the magic number might be), could i apply a bit of imperial sizing wax to the cartridges to ease extraction? or would this be unsafe and NFG like i suspect? hell, i'm not even sure this would help extraction in my situation.

would a 7.62x39 16" 8 twist barrel make a better candidate for a straight pull upper with its tapered case and lower pressures? i could have hawk make me some thin walled bullets.

a better solution would be to use an upper with a gas system, paired with a lower that cannot hold a second round. however, i doubt the game commission will find this acceptable if the upper and lower can separate. perhaps not even then. i'll call the man to inquire.

*** i recognize that most reading this view a straight pull upper as a wasted rifle. i have rifles that perform as they were intended. most animals i hunt are taken with a bow or flintlock up close. so this project is just for fun and because i can.
You could try to keep the pressure low and polish the chamber with Iosso bore paste. A couple of patches wrapped around a bush to get a tight fit, spin that in a drill with a short section of cleaning rod. Possibly run Slip grease on the bolt lugs and maybe after some use the lugs will smooth out and get easier to turn.

The 7.62x39 would probably work better with a tapered case and lower operating pressure.
 

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i think i'll avoid doing anything to the chamber that will degrade its ability to return to a gas operated rifle. the slip grease sounds like it's worth a try. i loaded up 50 of the 95 ttsx w/33.5 rl15. with their expansion velocity and the tests i've seen on this forum, i think they'll do just fine at the ranges i hunt if i'm anywhere in the neighborhood of 2700 mv.

has anyone looked at lantac's straight pull bcg? they've placed a spring over the bolt tail and removed the gas rings from the looks of it- "spring assisted bolt unlocking system.

www.lantac-usa.com/product-page/enhanced-bcg-straight-pull-223-5-56 is it possible i could do something similar w/ my carrier, remove the gas rings and add a spring? then throw a little slip grease on the bolt lugs. will removing the gas rings effect bolt alignment and accuracy? or is all the alignment taken care of by the critical dimensions forward of the cam pin hole?
 
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