[bj139]

Another thing I just remembered. I thought I seated these to the same length as factory Wolf 6.5 Grendel but I guess I was wrong.
They did not fit in a Pmag.
I did try them in the chamber with just thumb pressure on a disassembled upper and it closed and ejected easily.
At the range, I just single loaded them. They must be pretty close to the lands, if not touching.
The primers were still rounded.

 

[B4llsD33p]

Ok guys, Ive been messing with this quite a bit and I'm a little stuck. I'm having two issues, hopefully caused by the same thing, and pretty much has to do with cycling. Was working with this as a single shot since it wouldn't feed correctly, so I tried adjusting the gas block. Took the adjustment screw all the way out, and 9 times out of 10, the bolt won't lock back. I took it home, and realigned the gas block and started over, but to no avail. All of this time, I've been keeping an eye on my brass, and noticed (even with a mild charge and 85gr pills) i'm getting signs of pressure. Both times, I tried to get it to cycle (which it didn't), I would pull the trigger, and nothing. I pull the bolt back (which was a bitch), lo wand behold, jammed bullet, no indent on primer, and powder everywhere End of range day. Tried the same with a different bullet, same OAL, and I KNOW there will be more of a jump. Again, single shot, mild load. Case ejects, take a look, blown primer WAY too much pressure (this was 25.5gr 10x with 100gr TTSX. I think MV was about 2600). Since that was my lowest charge for those bullets, end of range day and bullet bulling time. So far, the list:

Won't cycle all the way
won't lock the bolt back
too much pressure at mild load
Bullets seem to jam, regardless of OAL.

Came home, made a few dummy cases, same OAL (recorded), put them in the chamber one at a time (pushing with my finger), took them out, and remeasured: same length
Did the same thing, but put the round in the mag, and let the bolt slam shut as you're supposed to. Did this multiple times, with multiple dummies and different bullets, and VOILA, each of the OALs were roughly 0.025" shorter (measured with comparitor). BUT none of the bullets were jammed, like when I was at the range (case AND bullet came out together and didn't have to use a rod to remove the stuck bullet. I'm thinking I have these pressure issues due to all of these bullets being jammed, rather than a jump.

I'm using a Lee Grendel seater (works great) and the Lee Grendel Crimp die. I noticed when I used the crimp, the case is a little too short and I can't get a full crimp to keep the bullet from moving when the bolt slams shut, but this also doesn't solve my extraction issues and needing the bold lock back on the last (or single) shot. Is this a spring/buffer issue? totally lost and could use some help.

 

[bj139]

Are you trimming about 0.1" from each case before starting?
Remove your upper, put a round in the chamber and just using your thumbs, close the bolt.
If it does not close easily, something is wrong. Pull back the charging handle and the round should eject easily.
If it does not, the case might be too long or the bullet may be too far out into the lands.
Your loads are about 10% lower than max. They shouldn't show high pressure.
Edit: Maybe when your bolt slams shut the bullets are hitting the feed ramp and being pushed into the case causing high pressure.

 

[MBW36330]

1) what's your case trim length ?
2) what's your oal with the 100ttsx ?
3) which sizing die are you using ?
4) are you using a shim between the shell holder and the bottom of the lfcd ?

Ok guys, Ive been messing with this quite a bit and I'm a little stuck. I'm having two issues, hopefully caused by the same thing, and pretty much has to do with cycling. Was working with this as a single shot since it wouldn't feed correctly, so I tried adjusting the gas block. Took the adjustment screw all the way out, and 9 times out of 10, the bolt won't lock back. I took it home, and realigned the gas block and started over, but to no avail. All of this time, I've been keeping an eye on my brass, and noticed (even with a mild charge and 85gr pills) i'm getting signs of pressure. Both times, I tried to get it to cycle (which it didn't), I would pull the trigger, and nothing. I pull the bolt back (which was a bitch), lo wand behold, jammed bullet, no indent on primer, and powder everywhere End of range day. Tried the same with a different bullet, same OAL, and I KNOW there will be more of a jump. Again, single shot, mild load. Case ejects, take a look, blown primer WAY too much pressure (this was 25.5gr 10x with 100gr TTSX. I think MV was about 2600). Since that was my lowest charge for those bullets, end of range day and bullet bulling time. So far, the list:

Won't cycle all the way
won't lock the bolt back
too much pressure at mild load
Bullets seem to jam, regardless of OAL.

Came home, made a few dummy cases, same OAL (recorded), put them in the chamber one at a time (pushing with my finger), took them out, and remeasured: same length
Did the same thing, but put the round in the mag, and let the bolt slam shut as you're supposed to. Did this multiple times, with multiple dummies and different bullets, and VOILA, each of the OALs were roughly 0.025" shorter (measured with comparitor). BUT none of the bullets were jammed, like when I was at the range (case AND bullet came out together and didn't have to use a rod to remove the stuck bullet. I'm thinking I have these pressure issues due to all of these bullets being jammed, rather than a jump.

I'm using a Lee Grendel seater (works great) and the Lee Grendel Crimp die. I noticed when I used the crimp, the case is a little too short and I can't get a full crimp to keep the bullet from moving when the bolt slams shut, but this also doesn't solve my extraction issues and needing the bold lock back on the last (or single) shot. Is this a spring/buffer issue? totally lost and could use some help.

 

[B4llsD33p]

Case trim length is 1.620", as suggested, average of 1.349 at the shoulder using .350" Hornady headspace gauge
I pulled all rounds, but I would guess I went with the suggested OAL of 2.300" with the TTSX, (didn't measure with the bullet comparitor, but if you want this measurement, lmk)
Sizing die is Redding 6.8 SPC die with .287" bushing (Starline brass)
No shim. I assume lfcd is "Lee Factory Crimp Die"? I'd like to see a picture of this. this MAY fix one of my issues by getting a tighter crimp.

I don't have any time to try what BJ suggested, maybe the next few days.

Should I try to trim a few cases to 1.610" and see what happens?

 

[MBW36330]

Trim to 1.61"
Seat 100ttsx to 2.292"- 2.295"
Die/bushing should be good to go
Try without crimping

You shouldn't need a crimp, but if you must, place approx .080 shim stock between the shell holder and the Lee factory crimp die (lfcd) as the 6.5G case length is 1.52" and the Six5 case is 1.61"

But again, you shouldn't need a crimp

Case trim length is 1.620", as suggested, average of 1.349 at the shoulder using .350" Hornady headspace gauge
I pulled all rounds, but I would guess I went with the suggested OAL of 2.300" with the TTSX, (didn't measure with the bullet comparitor, but if you want this measurement, lmk)
Sizing die is Redding 6.8 SPC die with .287" bushing (Starline brass)
No shim. I assume lfcd is "Lee Factory Crimp Die"? I'd like to see a picture of this. this MAY fix one of my issues by getting a tighter crimp.

I don't have any time to try what BJ suggested, maybe the next few days.

Should I try to trim a few cases to 1.610" and see what happens?

 

[B4llsD33p]

What would explain the bullet jumping into the lands when the bold closes? do I need more neck tension if I don't have to crimp?

 

[bj139]

Can you push a bullet into the case neck with your fingers?
If you can't you probably have enough tension.

The trim length was initially 1.620" but with chamber mod 1 it was changed to 1.610"
I initially missed that as well. it is buried about half way through this thread.

I would make sure your rounds fit the chamber before worrying about gassing.
With the upper off the lower, you can push the bolt closed with your thumbs and eject with the charging handle or even just your thumbs.
Advance the die a bit at a time until the bolt will just close then stop and size a few and test.
My die was a bit too long or the chamber is a bit too short so I had to grind my shellholder a bit to make the rounds fit in the chamber.
They should fit easily without letting the bolt fly.

I am using a .287" Wilson bushing and Starline brass and I can't push a bullet into the neck with my fingers.

 

[MBW36330]

I use a .289 bushing for the initial neck down of virgin 6.8 brass and a .286 bushing for the resizing of brass that's been fired in the Six5.

it might be a better idea to get a couple more bushings so you can experiment with neck tension instead of relying on a crimp to hold the bullet in place.

What would explain the bullet jumping into the lands when the bold closes? do I need more neck tension if I don't have to crimp?

 

[B4llsD33p]

I have a few bushings I can try. First thing I'll do is trim the brass, and do what BJ said working the bolt. Once I get results, I'll post. This kind of sucks cuz I've had good groups and didn't want to change anything, but it's all part of the game, eh?

 

[MBW36330]

Six5 is my all purpose AR
*bottom target is 95 vmax

I have a few bushings I can try. First thing I'll do is trim the brass, and do what BJ said working the bolt. Once I get results, I'll post. This kind of sucks cuz I've had good groups and didn't want to change anything, but it's all part of the game, eh?

 

[B4llsD33p]

Ok guys did a little work and here's what I found.

Trimmed two cases to 1.610"

Round 1:
100gr TTSX
COAL: 2.300"
Measurement using comparitor: 1.752

Took bolt out, pushed round in by hand and met some resistance, pushed a little harder and went in. Tough to estimated, but i'm guessing about a pound?
Extracted round, didn't feel too difficult to extract. Measurements were the same.


Round 2:
85 gr Sierra Varmint hpbt
COAL: 2.243"
Measurement using comparitor: 1.829"
Took bolt out, pushed round in by hand and met considerably more resistance than the TTSX and could not push it in by hand. Put the bolt in and pushed all the way forward (pics below, not sure how accurate that measurement is). Pushed quite hard and was able to get it in the chamber. As expected, took some effort to extract the round. Measurements after: COAL 2.232" Using comparitor 1.817"

Next idea?

 

[tbready]

Ok guys did a little work and here's what I found.

Trimmed two cases to 1.610"

Round 1:
100gr TTSX
COAL: 2.300"
Measurement using comparitor: 1.752

Took bolt out, pushed round in by hand and met some resistance, pushed a little harder and went in. Tough to estimated, but i'm guessing about a pound?
Extracted round, didn't feel too difficult to extract. Measurements were the same.


Round 2:
85 gr Sierra Varmint hpbt
COAL: 2.243"
Measurement using comparitor: 1.829"
Took bolt out, pushed round in by hand and met considerably more resistance than the TTSX and could not push it in by hand. Put the bolt in and pushed all the way forward (pics below, not sure how accurate that measurement is). Pushed quite hard and was able to get it in the chamber. As expected, took some effort to extract the round. Measurements after: COAL 2.232" Using comparitor 1.817"

Next idea?

My $.02, shoulder not set back far enough. Did you clean melonite reside out of chamber? Had to polish mine some with Iosso to get pressure to drop.

 

[MBW36330]

Are you able to chamber the cases prior to seating a bullet?

 

[constructor]

Sounds to me like the 85s are set out too far and jamming the lands. seat them deeper and try it again.

 

[bj139]

It sounds like your 85 gr Sierra rounds are too long and hitting the lands.
The TTSX seems like an OK COL.

Try the sized brass alone for chamber fit as MBW suggests.

I had to grind the top of the shellholder a bit to even get the bolt to close on my Six5.
When you seat the bolt can you see the bolt lugs turning fully into battery behind the receiver lugs?

I shot my Six5 yesterday and got 2895fps average for 10 shots with an 85gr Sierra and 1.6cc LeveRevolution with no high pressure signs.
I tried out my Labradar chronograph for the first time. I like it so far.

 

[bj139]

Sounds to me like the 85s are set out too far and jamming the lands. seat them deeper and try it again.

Beat me by 2 minutes.

 

[B4llsD33p]

Are you able to chamber the cases prior to seating a bullet?

Nope. Also tried to chamber an empty, unsized fired case, and get the same result. Bolt won't close.

 

[B4llsD33p]

Trimmed a fired case to 1.610", same result, won't chamber. I"m not going to worry about the 85 grainers until I can get an empty case to chamber correctly.

 

[tbready]

Trimmed a fired case to 1.610", same result, won't chamber. I"m not going to worry about the 85 grainers until I can get an empty case to chamber correctly.

Set the shoulder back further. Headspace is still too tight. Unsized fired case is going to stick. Size fired case shoulder back .002-.003''