88 TMK Loading Thread

[rafiki]

Does anyone have a cut-away photo of the 88 TMK?

Also, does anyone have a suggested recipe for load/powder for running it in a Tikka with an 18" PBB barrel? I'm looking for something to start with that is the easy button.

which cartridge? everyone in this thread is working on the recipes...
i had light ejector marks on a brand new 16.25" PBB 22 creed yesterday with min 4831sc / staball hd loads so am going to run some more factory 80 elds thru it to get the round count up before revisiting

 

[Nine Banger]

Also, does anyone have a suggested recipe for load/powder for running it in a Tikka with an 18" PBB barrel? I'm looking for something to start with that is the easy button.

Every post of mine in this thread is with a Tikka and an 22 Creed 18" PBB barrel...

 

[NWBLKTAIL]

I'm trying to get to the same conclusion and I think the answer is generally yes. I'm at sea level and I'm concerned about that...

Same livin on the coast, but I ordered brass and 100 bullets. I’ll spin the barrel on, if it doesn’t work out there are plenty of guys on here who will use them.

 

[FB Trout]

Looks good... Assuming 1:8. Care to share your DA or Altitude?

Yes, 1:8 twist and DA of 4300'

 

[glock233]

which cartridge? everyone in this thread is working on the recipes...
i had light ejector marks on a brand new 16.25" PBB 22 creed yesterday with min 4831sc / staball hd loads so am going to run some more factory 80 elds thru it to get the round count up before revisiting

I’m an idiot. 22CM

 

[rafiki]

any help/advice on diagnosing my issue or what you’d try next?

tikka 22cm
PBB 16.25” 1-7.5tw .120 FB (brand new)
rs1.2
scythe ti
DA 3,150 ft

first 6 rnds thru the barrel were factory 80 ELDX to zero scope avg 2,932 fps

load 1
-88 tmk
-43.5 gr stball hd
-peterson lrp (unfired)
-cci 200
-2.7 coal
-2,600fps

load 2
-88 tmk
-38.5 gr h4381sc
-peterson lrp (unfired)
-cci 200
-2.7 coal
-2,524 fps

only shot a couple rnds of each hand load bc i saw light ejector swipes and heavier bolt lift. shots were spaced out 1-2 minutes. bullets were seated to 30 thou jump in my chamber based on modified case and hornady oal gauge.
lots of new variables at play so not sure if i just need the barrel to break in more or if i should be looking at one specific element on the loads/rifle system.

 

[mtnbound]

Anyone shot them in an 8 twist barrel?

I couldn't get the 88 eldm's to shoot, but hoping these may work.

Ran in my 1-8 Tikka with no issues but COAL needs to be 2.4” min IME.

 

[AndrewMT34]

Understood, I'll be shooting them in a 22creed, so COAL shouldn't be a problem.

 

[43.6N]

88TMK
223 Wylde. 18” PBB
1/7.5 twist
Seated 2.490”
Lapua Brass
CCI 450

23.0gr 8208XBR
-2657fps

23.0gr H4895
-2685fps

23.5gr Varget
-2634fps

I zeroed off the Varget load.
Then took it out to distance to eval the 0.525 bc.

Still conditions.
3200ft DA

746yds - 6.2 mils
First round impact.
Retained velocity 1600fps.

1130yds - called for 12.8 mil.
Ended up using 12.5 mil.
Retained velocity 1232fps.

that’s good enough for me.
I’ll probably hunt bears with the Varget load this spring.

 

[amassi]

any help/advice on diagnosing my issue or what you’d try next?

tikka 22cm
PBB 16.25” 1-7.5tw .120 FB (brand new)
rs1.2
scythe ti
DA 3,150 ft

first 6 rnds thru the barrel were factory 80 ELDX to zero scope avg 2,932 fps

load 1
-88 tmk
-43.5 gr stball hd
-peterson lrp (unfired)
-cci 200
-2.7 coal
-2,600fps

load 2
-88 tmk
-38.5 gr h4381sc
-peterson lrp (unfired)
-cci 200
-2.7 coal
-2,524 fps

only shot a couple rnds of each hand load bc i saw light ejector swipes and heavier bolt lift. shots were spaced out 1-2 minutes. bullets were seated to 30 thou jump in my chamber based on modified case and hornady oal gauge.
lots of new variables at play so not sure if i just need the barrel to break in more or if i should be looking at one specific element on the loads/rifle system.

Go shoot another 80~ rounds before revisiting.
You’re well under book max and getting low velocity and high pressure. Make sure your chamber is clean as well as your suppressor


Sent from my iPhone using Tapatalk

 

[wind gypsy]

any help/advice on diagnosing my issue or what you’d try next?

tikka 22cm
PBB 16.25” 1-7.5tw .120 FB (brand new)
rs1.2
scythe ti
DA 3,150 ft

first 6 rnds thru the barrel were factory 80 ELDX to zero scope avg 2,932 fps

load 1
-88 tmk
-43.5 gr stball hd
-peterson lrp (unfired)
-cci 200
-2.7 coal
-2,600fps

load 2
-88 tmk
-38.5 gr h4381sc
-peterson lrp (unfired)
-cci 200
-2.7 coal
-2,524 fps

only shot a couple rnds of each hand load bc i saw light ejector swipes and heavier bolt lift. shots were spaced out 1-2 minutes. bullets were seated to 30 thou jump in my chamber based on modified case and hornady oal gauge.
lots of new variables at play so not sure if i just need the barrel to break in more or if i should be looking at one specific element on the loads/rifle system.

Did you lather those things up with lube before sticking them in your chamber? About the only thing I can think of is having greasy chamber/brass so you're getting a lot of bolt thrust.

 

[justin davis]

Is it pretty typical for the GT to produce the same speeds as 22 Creed if all the parameters are the same?

No. I’ve heard within a few hundred fps all things equal but not the same speeds

 

[rafiki]

yea i think i’m not so smart…just looked and saw some light markings on the factory cases that i didnt catch. checked the bolt and found some debris/grit on my bolt face. cleaned everything and will send some more factory rounds before going back to the handloads. thank you guys!

 

[B_Reynolds_AK]

5.56 NAS3 case & 88 TMK

Going to pressure test some loads this evening with N150.

 

[B_Reynolds_AK]

Well,
A couple days ago I ran a pressure test with ADI Brass, Fed 205 primers, N150 and the 88 TMK’s. I went up to 26.0 then backed off to 25.0 and shot another 15 of them. No issues, no sticky bolt lift. Some cratering of the primer, but I generally get some of that even on the factory ADI ammo. Velocity is 2686 fps.

I loaded up the NAS3 cases with 25, 26 and 27.0 of N150, based on the appx 10% larger case capacity stated by Shell Shock.
I fired all three rounds and got 2704, 2764 and 2840 fps. However, all three primers were pierced.

Edit: on further inspection and research, these are “cookie cutter” holes, often associated with the excessive headspace by a shoulder that is set back too far. These cases have a shoulder that is as much as .014” shorter than a fire formed case.

Now I’m not sure where the issue is, seeing how 25 & 26 were ok in the Adi brass. Maybe something to do with the characteristics of the alloy cases? Too much headspace? But I’ve never pierced a primer in a brass case at the same pressure.

Below is a photo showing, from left to right, 25.0 - 26.0 - 27.0. The ADI is a 25.0 load.

 

[Thegman]

Here is a post on SH that addresses potential issues with alloy cases.


https://www.snipershide.com/shooting/threads/opinions.7269453/post-12340018

Not sure if this is the case with your rifle chamber/NAS3 cases, or if it would lead to the issue you're having even if it were, but another poster mentioned something I thought was interesting about the NAS3 cases he had:

He just had a 233 AI chambered which has about a 0.004" crush fit and takes some force to chamber a factory cartridge...but he noted that the NAS3 cases chambered without any extra effort. They sound like they could create an excessive headspace condition, at least in his case.

I had some sticky unchambering with the few I tried, with normal pressure loads. In hindsight I'm wondering if that may have been a similar issue.

 

[43.6N]

Well,
A couple days ago I ran a pressure test with ADI Brass, Fed 205 primers, N150 and the 88 TMK’s. I went up to 26.0 then backed off to 25.0 and shot another 15 of them. No issues, no sticky bolt lift. Some cratering of the primer, but I generally get some of that even on the factory ADI ammo. Velocity is 2686 fps.

I loaded up the NAS3 cases with 25, 26 and 27.0 of N150, based on the appx 10% larger case capacity stated by Shell Shock.
I fired all three rounds and got 2704, 2764 and 2840 fps. However, all three primers were pierced.

Now I’m not sure where the issue is, seeing how 25 & 26 were ok in the Adi brass. Maybe something to do with the characteristics of the alloy cases? Too much headspace? But I’ve never pierced a primer in a brass case at the same pressure.

Below is a photo showing, from left to right, 25.0 - 26.0 - 27.0. The ADI is a 25.0 load.
View attachment 1038954

Try again with cci 450 magnum primers or nato AR primers.

Are the nas3 cases showing any shoulder/headspace elongation after firing? Or are they too tough to fire form in the chamber?

 

[B_Reynolds_AK]

He just had a 233 AI chambered which has about a 0.004" crush fit and takes some force to chamber a factory cartridge...but he noted that the NAS3 cases chambered without any extra effort. They sound like they could create an excessive headspace condition, at least in his case.

Are the nas3 cases showing any shoulder/headspace elongation after firing? Or are they too tough to fire form in the chamber?

That’s interesting. I’ll take some measurements and see wha I can diagnose. At the very least, I know that the ADI brass and load work very well and this may just be a failed experiment.

Edit to add measurements:
ADI Unfired Shoulder: 1.361
Fired Shoulder: 1.365

NAS3 Unfired: 1.351 - 1.355
Fired: 1.359 - 1.362

It could certainly be that this could create an excessive headspace issue, seeing how some of the case shoulders are as much as .014”back from a fire formed shoulder in this chamber.

I forgot to mention that the last round I went to fire, didn’t. Excessive shoulder setback, in this case as it came from the factory, could lead to this as well.

 

[sierracharlie338]

Speed isn't everything. I'm looking for an accurate load with little work up without pushing for speed. If the 88's don't work, I will try the 80.5 Fullbore. More speed than the 22 ARC and more barrel life than the 22CM is my first priority. Long life and easy load maintenance.

Jay

You’re describing the GT based off what I have seen. Let us know how it shoots!

 

[Schmo]

Well,
A couple days ago I ran a pressure test with ADI Brass, Fed 205 primers, N150 and the 88 TMK’s. I went up to 26.0 then backed off to 25.0 and shot another 15 of them. No issues, no sticky bolt lift. Some cratering of the primer, but I generally get some of that even on the factory ADI ammo. Velocity is 2686 fps.

I loaded up the NAS3 cases with 25, 26 and 27.0 of N150, based on the appx 10% larger case capacity stated by Shell Shock.
I fired all three rounds and got 2704, 2764 and 2840 fps. However, all three primers were pierced.

Edit: on further inspection and research, these are “cookie cutter” holes, often associated with the excessive headspace by a shoulder that is set back too far. These cases have a shoulder that is as much as .014” shorter than a fire formed case.

Now I’m not sure where the issue is, seeing how 25 & 26 were ok in the Adi brass. Maybe something to do with the characteristics of the alloy cases? Too much headspace? But I’ve never pierced a primer in a brass case at the same pressure.

Below is a photo showing, from left to right, 25.0 - 26.0 - 27.0. The ADI is a 25.0 load.
View attachment 1038954

Well that’s frustrating!

Do you know what you NT is? If it’s excessive, I wonder if that is contributing.

Also, you might call John @ Blackarc Munitions. He loads these cases for some of his standard retail offerings. I’m sure he’d have some insight.