TC Impact will not shoot. looking for ideas

[hockeyref]

New breech plugs delivered, testing will resume once temperatures are reasonable.... for the record, 20 - 30 degrees or anytime it's raining is not considered reasonable.

 

[Retiredusn]

New breech plugs delivered, testing will resume once temperatures are reasonable.... for the record, 20 - 30 degrees or anytime it's raining is not considered reasonable.

Please keep us updated on how it works out.

 

[Montana Muzzleloader]

My son has an Impact SB. So far it has shot good with 260 grain Harvester PT Gold bullet with black crush rib sabot & any reasonable charge of Blackhorn 209. He practiced with 60 grains by volume when he was younger & shoots 90 now.

 

[Montana Muzzleloader]

All of my T/C's shot the best by swabbing with a wet patch and 2 dry patches between shots with Goex and 777. What is your cleaning routine while shooting?

Great advice

 

[hockeyref]

Ok so resurrecting my thread...
Went out today with a brand new breech plug, a horn full of Graf's 3F, and a box of Hornady 385gr Great plains bullets. tested with 90g load at 100 yards. For the first seven shots I pulled the breech plug after every shot and ran 1 wet and 3 dry patches between shots. I used windex until it started freezing then switched to 93% isopropyl alcohol. It was promising as I no longer had a pattern, but... (always a but)..... the 10 shots fired strung ~8" vertically (width of the string was ~2"). It was acting like it wanted to group, but I wasn't sure what to tweak to address the vertical.

Suggestions?

 

[txhunter58]

1). Do not use conicals. Use sabots. That takes the QLA out of the equation.
2). Do not remove the breech plug after every shot. It is absolutely not needed.
3). Run a wet patch, then a dry patch after each shot and then reload.

Do that and then tell us what happened.

 

[txhunter58]

This diagram Shows why a QLA can have trouble shooting a conical.

 

[rangerod]

View attachment 27846
This diagram Shows why a QLA can have trouble shooting a conical.

Great post.

 

[Blacksheep]

IMHO your changing way to much shot to shot . Going by your last post your string is almost completely vertical . Let’s look at the stock / receiver contact. Look at the screw on the bottom of the stock is it tight ? I ask this as I see no reference to it in your post . Step two take a note card and slide it down the barrel channel is something contacting the barrel ?
I would suggest that all you do is lick a patch wipe it turn it over and dry patch .

Most tc barrels are .500-.501 so I would try either Hornady SST 250-300 grain in a Harvester sabot which should give a diameter of .504 +|-.

 

[DavidAR10T]

I only have 3 BP rifles that I purchased within months of that model hitting the store shelves:
NEF SideKick w/25ACP breech plug [received their latest breech plug uses WIN 209 primers, last month, untested] 1.8" @ 100yds 5 shot groups
T/C IMPACT Gen 1 Sub 1"
T/C IMPACT SB (Gen 2) untested, will do this spring

I started with all the latest and greatest CRAPOLA(for me) bullet/powder/primer combos . Today, I am sold on this load:
Barnes 290gr Barnes Spit-Fire T-EZ Bullet (that's the flat base for those in Rio Linda)
77gr weighed of BlackHorn 209
CCI 209 Magnum primer
If'n scope mount, scope rings, scope and assembled rifle are good to go:
If you cannot shoot under 2.5MOA 5 shot groups, without cleaning/swabbing/yada, at 100yds, then I say the rifle has a problem.

Best to you.

 

[DavidAR10T]

T/C flash channel is 1/8th inch. Once the flash HOLE is .036 or larger its time for a new plug.

IMPACT and IMPACT SB bp are of a completely different spec.
I'm at work on my day off, but will post info asap.
When I was first cussing at clouds using T-7 crapola, I couldn't get
a hypodermic needle down the flash hole even when clean. I believe
the needle gauge was #21, 0.032". Wife was a Peds ER Nurse 37yrs.

 

[GM54-120]

Please read what i typed again

 

[hockeyref]

Guys, I am well versed on why the QLA sucks.... quite honestly, a hollow base conical might just obturate the skirt enough to mitigate "some" of the mis-alignment the same way a sabot base might. Doesn't change the fact that the QLA sucks. I do know someone with a lathe that would be willing to remove and re-cown, but I'm not there yet.

TXhunter....... did you read my original post? This turd has been shooting shotgun patterns with multiple combos of bullets and sabots from the first shot down the pipe. In fact, the final shot this past outing, just for S&G, was same charge behind a 240 XTP in a Green Harvester P/N H5044G - Impact was good for elevation but 6" left of POA (the Conicals were impacting 3" right of POA).

BlackSheep.... how am I changing too much? I have been fairly methodical in testing the same way I would develope a mid\LR load for one of my prone rifles. In this latest test I used a charge that I tried with all of those different bullets and sabots. I am shooting what is basically a series of clean\cold bore shots. The only change I made to the rifle is the breech plug (that needed replaced as original was blocked and unusable) and a different bullet which was on the list to test anyway. Pulling the breachplug allowed me to just push a patch straight through without risk of pushing crud into the the flash hole. Again, I wanted to basically shoot 5 shot strings from a clean dry bore.

Just to list what has been tried already:
Powders
Grafs 2F & 3F 60-110 gr in 10gr increments
777 (loose) 2F & 3F 60-110gr in 10gr increments
777 pellets (I hated them so didn't pursue them very far)
Primers
Rio, Cheddite, Federal, and Winchester 209 primers
Bullets:
Hornady 250gr & 300gr SST
240gr XTP bullets (44 and 45 cal)
240gr cast .430 Keith bullets in sabot
TC ShockWave
CVA 245gr Power Belts
CVA 290gr powerbelts
Hornady 385gr great plains

Sabots:
Harvester Green Crushed rib ,429-.430 H15044GR
Harvester High Pressure .429-.430 H5044Gsabots
Harvester Crushed Rib .451-.452 H15045BR

Scope base screws have been checked and the scope is known good, tested on other rifles.

 

[DavidAR10T]

Please read what i typed again

I really, really, really, I mean it, back in the day, for two years, used to teach OBSERVATION.
HONEST.

Sorry, sir. In my defense I have stated in one or more threads that I am dumber than a bag of hammers, or to the effect.
I do know that T/C did away with the 0.125 flash channel on the two IMPACT BPs and went with the Dodge Hemi design.

 

[GM54-120]

What is the size of the flash channel now since you said its changed?

 

[txhunter58]

I will admit I may have missed something in your original post but following the thread I was hoping that it was the breechplug.

What I can’t figure out is why you would remove your new breechplug after every shot. That does nothing to help you and it might hurt.

 

[hockeyref]

GM-54 ... I can only hope it's closer to spec than the original. I don't have pin gauges and cannot find drill index at the moment.

TX as I said, I was basically taking the bore down to essentially "cold bore shot clean" and that was easiest to accomplish by pulling the plug. Also allowed me to clean and flush any crud out of the plug. I have a .308 bolt rifle that consistently puts the clean cold bore shot .75moa low and .75 moa left then drops all successive shots onto POA. Dope book recording location of every clean bore shot confirms the behavior. If I ever hope to take this rifle out to hunt it is gonna be clean so I see no reason not to expect it to drop it's first shot out of a cold clean bore into the same (general) spot even if it may not ultimately be in the group of successive dirty bore shots.

FWIW I did run 3 consecutive shots without patching at all, just dump the powder, shove the bullet down and let it scrape the fouling down onto the top of the powder charge. They exhibited the same stringing.

 

[brad502a]

I for giggles would change the scope. You say it is known good, change it anyway. One more variable eliminated.

 

[DavidAR10T]

What is the size of the flash channel now since you said its changed?

I should not have been working in the lab(on my day off) and dashing back and forth in this forum.
Everything looks same/same.
0.125" Flash Channel is @ 0.510" in depth
0.0XX" Flash Hole is @ 0.350" in depth

Well, maybe I can still contribute to the thread.
The proper o-ring replacement is McMaster #1201T49:
Chemical-Resistant Viton® Fluoroelastomer O-Ring, Mil. Spec., 3/32 Fractional Width, Dash Number 113

Why didn't I just stay in bed?
Best to all.

 

[Frosty861]

GM-54 ... I can only hope it's closer to spec than the original. I don't have pin gauges and cannot find drill index at the moment.

TX as I said, I was basically taking the bore down to essentially "cold bore shot clean" and that was easiest to accomplish by pulling the plug. Also allowed me to clean and flush any crud out of the plug. I have a .308 bolt rifle that consistently puts the clean cold bore shot .75moa low and .75 moa left then drops all successive shots onto POA. Dope book recording location of every clean bore shot confirms the behavior. If I ever hope to take this rifle out to hunt it is gonna be clean so I see no reason not to expect it to drop it's first shot out of a cold clean bore into the same (general) spot even if it may not ultimately be in the group of successive dirty bore shots.

FWIW I did run 3 consecutive shots without patching at all, just dump the powder, shove the bullet down and let it scrape the fouling down onto the top of the powder charge. They exhibited the same stringing.

I'd give the original breech plug 2 minutes for interference.

Sorry, I could not resist!

Best of luck,

Frosty