Impact Action Hitch on Opening

[Hawk in WY]

I love my Impact actions. This is not a complaint.

Impact short action shooting 7 Saum.

There is a decided hitch at the top on opening. It is more pronounced with hotter loads. No other pressure signs.

Is this cock on opening normal or would a different trigger hanger make this less pronounced?

If it went away completely, I would be a very happy camper.

 

[Supersubes]

I love my Impact actions. This is not a complaint.

Impact short action shooting 7 Saum.

There is a decided hitch at the top on opening. It is more pronounced with hotter loads. No other pressure signs.

Is this cock on opening normal or would a different trigger hanger make this less pronounced?

If it went away completely, I would be a very happy camper.

Your chamber is too small at the back end, or your die is not doing enough work at the web area of the case.

 

[DangerRanger]

Yep Sounds like a clicker ^^^^

How many times has the brass been fired

 

[OREGUN]

Your chamber is too small at the back end, or your die is not doing enough work at the web area of the case.

You’re suggesting what the benchrest crowd calls “clickers”.

Not sure it’s related to the hanger….isn’t that a “hitch on close” that people complain about?

You could try a small base die (the usual solution for clickers) or new brass.

 

[Hawk in WY]

Your chamber is too small at the back end, or your die is not doing enough work at the web area of the case.

I suspect that may be the problem. That would explain why hotter loads make things slightly worse.

Brass is on the second firing. Chambering and extraction are just fine. The problem is the hitch at the top.

I would expect a tight chamber at the back would interfer with extraction and why just at the top of the bolt lift?

 

[Supersubes]

I suspect that may be the problem. That would explain why hotter loads make things slightly worse.

Brass is on the second firing. Chambering and extraction are just fine. The problem is the hitch at the top.

I would expect a tight chamber at the back would interfer with extraction and why just at the top of the bolt lift?

Textbook small chamber. The hitch is the bolt handle hitting the extractor cam, which gives you a lot of mechanical advantage and .030-.050 of rearward bolt travel. Thats all the work thats needed to free the case. Its a pretty easy job to have your gunsmith hone it.


If pressure was actually excessive, the case will be long due to lug setback and the case yielding to its new larger shape. The bolt will be hard to lift for its entire travel, because the case head is thrusting hard against the bolt face.

 

[Hawk in WY]

Does it happen on an empty chamber? After dry fire?

Yes, it does. On several different actions. I assumed this was cock on open which is why I thought the trigger hanger might be the source of the problem, if it can be called a problem. I am running the stock trigger hanger that ships with Impact actions. I understand others are available.

To address another comment, the hitch is pronounced enough that you would not miss it running the bolt fast.

 

[Hawk in WY]

That's where the primary extraction is. When the first rearward pull on the case is. It's breaking the fat web loose of the chamber.

That makes perfect sense.

Textbook small chamber. The hitch is the bolt handle hitting the extractor cam, which gives you a lot of mechanical advantage and .030-.050 of rearward bolt travel. Thats all the work thats needed to free the case. Its a pretty easy job to have your gunsmith to hone it.


If pressure was actually excessive, the case will be long due to lug setback and the case yielding to it new large shape. The bolt will be hard to lift for its entire travel, because the case head is thrusting hard against the bolt face.

By hone "it," I assume you are referring to the chamber. Measure twice. Cut once.

Bolt lift except for the final maybe half inch is perfectly normal.

 

[Supersubes]

That makes perfect sense.

By hone "it," I assume you are referring to the chamber. Measure twice. Cut once.

Bolt lift except for the final maybe half inch is perfectly normal.

A little confused you said this started on the second firing, but you also said it does it on an empty chamber? If you're feeling exactly the same thing on an empty, it’s not a chamber die issue.


Small chambers aren't uncommon. You usually run into it when someone designs a chamber around a certain make of brass, and then new brass is used. I ran into this just a few days ago. My 25 PRC reamer works great with Hornady brass, but I needed to hone the chamber slightly to use Lapua. I didnt design the reamer, but it was designed well before Lapua made 6.5 PRC brass.

 

[Hawk in WY]

If it happens without a case/ cartridge in the chamber then it isn't a chamber/ die incompatibility problem like being discussed.

Sear height and cocking pressure can cause a stiff feeling which is what you're referring to as the trigger hanger issue. But that would occur when the sear is cocking the firing pin. I don't have an Impact action so I don't know, but all my two lug actions cock on closing. So this stiff cocking would not happen on opening or lifting the bolt. Does the Impact cock on opening? I didn't think so.

Good question. To be clear, the hitch without a fired case in the chamber is discernable but very minor and probably is something you would not notice running the bolt fast. The hitch after firing is not something you would miss.

 

[Hawk in WY]

A little confused you said this started on the second firing, but you also said it does it on an empty chamber?

See comment below. The hitch was there on the first firing using light loads waiting for the barrel to speed up but nothing like on the second firing which was with loads meant for business. Hot loads definitely make matter worse which is why I believe clickers is the answer.

The slight hitch with an empty chamber may well have something to do with the trigger hanger. If that was my only problem, I would ignore it.

 

[Hawk in WY]

This is one of those situations where it's nice to have a good smith/ buddy close to you that can look at the rifle first hand. Sometimes trying to explain this stuff to people on the internet is like trying to explain what sex feels like to a virgin. Squishy.

Agreed. Not many good gunsmiths here in this part of Wyoming, but there is one nearby in Idaho. I now have enough information to discuss this with him. Thank you.