17 TAC brass forming issues

The Virginian

The Virginian

New member
I have a 17 TAC that I ordered from Mike at Dtech. I'm dying to get this rig to the range and I've hit an absolute speed bump on forming brass. I believe I'm within specs on the brass all the way around & I'm using Redding dies with IMI brass. Necking down .223 -> 20TAC -> 17 TAC.

I've reached out to a PM member (17Tactical) who's heavy into Dtech & 17s. He was kind enough to send a fireformed case for me to measure from.
Mine on the left and the correct brass on the right that does feed properly.

Mine on the left and the correct brass on the right.


He stated 1.7465" is the max total case length and 1.4345" is the base to shoulder length. I'm in the spec range within 4/1000. I'll try to get exactly in spec. I'm not sure what else I can so. I'm so close to where I need to be.


I welcome any advise.
 
Originally Posted By: The VirginianI have a 17 TAC that I ordered from Mike at Dtech. I'm dying to get this rig to the range and I've hit an absolute speed bump on forming brass. I believe I'm within specs on the brass all the way around & I'm using Redding dies with IMI brass. Necking down .223 -> 20TAC -> 17 TAC.

I've reached out to a PM member (17Tactical) who's heavy into Dtech & 17s. He was kind enough to send a fireformed case for me to measure from.
Mine on the left and the correct brass on the right that does feed properly.

Mine on the left and the correct brass on the right.

He stated 1.7465" is the max total case length and 1.4345" is the base to shoulder length. I'm in the spec range within 4/1000. I'll try to get exactly in spec. I'm not sure what else I can so. I'm so close to where I need to be.

I welcome any advise.

... and your problem is???

4 thou is nothing - you are ready to load it.
 
The bolt does close and it can be fired, just a lot of resistance on trying to extract it. I was concerned that there would be an issue firing it like this.
 
Originally Posted By: The VirginianThe bolt does close and it can be fired, just a lot of resistance on trying to extract it. I was concerned that there would be an issue firing it like this.

When you say resistance extracting, I am confused - it is in a AR configuaration, yes? If so, do you have the gas port closed? How do you know that the extraction is hard??
 
Originally Posted By: biggen0_8Are you saying that your having feeding problems with your brass?

Yes, it load but will not eject because it's getting stuck. I have to gently tap the T charging handle with a rubber mallet to dislodge the case. I believe the culprit here might be a slight swelling at the shoulder. If you look closely at the picture, you can see it slightly.
 
Originally Posted By: CatShooterOriginally Posted By: The VirginianThe bolt does close and it can be fired, just a lot of resistance on trying to extract it. I was concerned that there would be an issue firing it like this.

When you say resistance extracting, I am confused - it is in a AR configuaration, yes? If so, do you have the gas port closed? How do you know that the extraction is hard??



Yes, it is an AR and bolt is an incorrect term. Mea culpa. The gas port I'm unfamiliar with so i can't answer that. I'm unable to extract with the charging handle because it's a pressure fit which requires tapping to get it dislodged.
 
Originally Posted By: The VirginianOriginally Posted By: CatShooterOriginally Posted By: The VirginianThe bolt does close and it can be fired, just a lot of resistance on trying to extract it. I was concerned that there would be an issue firing it like this.

When you say resistance extracting, I am confused - it is in a AR configuaration, yes? If so, do you have the gas port closed? How do you know that the extraction is hard??



Yes, it is an AR and bolt is an incorrect term. Mea culpa. The gas port I'm unfamiliar with so i can't answer that. I'm unable to extract with the charging handle because it's a pressure fit which requires tapping to get it dislodged.

OK... now this may sound weird, but - if the loads are too light for the way hte gun is set up, the gas will only push a little, so the bolt goes only part way back, and then goes forward again, pushing the fired case back into the chamber, but it is now a bit larger, so it "wedges" into the chamber.

These are "Wedge jams".

I had this happen with a 223 in my Colt SP-1/CAR when I was trying to make light loads.

What powder, charge, and bullet are you using - and is it a starting load, or max or close to max.

If your starting loads are very light", increase them - if they are already heavy, let me know, and we'll go from there.

 
Catshooter,

I haven't fired a round yet. I ordered Todd Kindler's 17s book and he's published some loads to work with. What little is on the net states the TK's load are HOT and you should start slow and work your way up.

With that said I'm going to work with Vargat, using Channing Nagel's 25 gr T-000 bullets. I've had goos success with my 17 Mach IV using his bullets. I may have to go with a 30 gr., we'll see... The high end of my load should be 25.5g of Varget at 4106 fps. For fireforming I was going to start at 24.0 gr of Vargat. I have a ton of Zmax 25 gr to use for fireforming.

I tend to error on the side of caution and didn't want to try to fire this rig yet till others (that I respect) weighed in on whether it was safe or not. My guess is I'll be fine and after they're fireformed, They should extract fine.
 
Here's the specs on the TAC 17. PM member 17Tactical has been a huge help to me as I learn this wildcat game. He stated "DTECH Uppers prefer 1.7465" total case length & 1.4345" length (from base to start of shoulder), anything longer and you will have trouble with these uppers." So I'm using his proven guidelines.

I appreciate everyone's input. My nads tend to shrink up a bit when I'm not 100% positive on something.

 
Originally Posted By: The VirginianCatshooter,

I haven't fired a round yet. I ordered Todd Kindler's 17s book and he's published some loads to work with. What little is on the net states the TK's load are HOT and you should start slow and work your way up.

With that said I'm going to work with Vargat, using Channing Nagel's 25 gr T-000 bullets. I've had goos success with my 17 Mach IV using his bullets. I may have to go with a 30 gr., we'll see... The high end of my load should be 25.5g of Varget at 4106 fps. For fireforming I was going to start at 24.0 gr of Vargat. I have a ton of Zmax 25 gr to use for fireforming.

I tend to error on the side of caution and didn't want to try to fire this rig yet till others (that I respect) weighed in on whether it was safe or not. My guess is I'll be fine and after they're fireformed, They should extract fine.

Virg...

I am confused (it doesn't take much)...

So is that the NEW, unfired cases will go in, and are hard to remove??

Is the IMI brass new or fired brass??

 
Will it load one of your cartridges easily and extract easily without being fired? Or does your cartridge have some resistance being loaded and extracted unfired?
 
To date I have not loaded any cartridges. I'm only working on my brass to see if it feeds and extracts in the AR. Tough to tell with an AR when you load the (unloaded) brass into it I'm getting very little resistance. When I try to eject it, it's a bear to pull back on the charging handle to eject. I hope this clarifies what I wrestling with.

Eric
 
Originally Posted By: The VirginianTo date I have not loaded any cartridges. I'm only working on my brass to see if it feeds and extracts in the AR. Tough to tell with an AR when you load the (unloaded) brass into it I'm getting very little resistance. When I try to eject it, it's a bear to pull back on the charging handle to eject. I hope this clarifies what I wrestling with.

Eric

OK... that is clear. Is the IMI brass new, or fired?

Do you have a FL die with your doe set - if so, use it and try the cases.

 
OK, so If I understand you correctly, if you chamber a piece of your brass (unloaded) your not sure if it has much resistance, but trying to extract this same piece of unloaded brass is hard?

Have you measured the shoulder diameter and base/web diameter of your brass and the piece that was sent to you, that works fine?
 
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The IMI are USED fired cases and I was told they would be a good .223 case to neck down because of their durability and thickness. Yes they will go in and are very hard to extract. My ability to write what I'm dealing with seems to be lack luster. My apologies...

I'm starting to think that the brass may be too thick. Maybe I should order some TAC 20 Dakota/Lapua brass and have another go with it? Possibly the curve ball being thrown my way here is USED brass and too thick?
 
OK, in my mind, your once fired brass is the issue. Do you have any unfired brass to try?

I wonder if you used small base dies on your IMI brass first, if that would help you?

I suggest that you try some new unfired brass at this point.
 
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