Last Friday,...courtesy of our esteemed member, MacEntyre...I finally got a close look at a Tisas GI Model. Overall, I was impressed with the gun. There were a couple minor issues that were mainly aggravation and easily corrected...neither of which would be a deal breaker if I had an intention of buying one of the pistols.
On disassembly, the plunger assembly launched out of the plunger tube because the spring didn't have the required dogleg kink. I corrected it on the spot.
During reassembly, the slidestop presented a little problem due to the rear angle of the lug. I didn't correct that, but it's an easy fix should Mac decide to tackler it, and not a major problem to use a credit card to push the plunger back into the tube if he doesn't.
A little more extractor deflection than I like to see, but if it doesn't cause a problem with feed/RTB, it can be ignored, or easy to correct if it does.
The hammer hooks weren't bearing evenly on the sear crown. That became evident when I lightly boosted the hammer and the trigger immediately went from about 6-7 pounds to double that. More light boosting had it on its way to being equalized, and I'd say that a couple hundred rounds to let everything wear in and seat and Mac will end up with a clean 5-5.5 pound rollout trigger...perfect in my world for a duty gun.
As I said...minor gripes.
The oddest issue popped up when reassembling the frame. With the hammer full forward, the sear feet were kicked out, making installation of the mainspring housing impossible when the sear spring was installed. In order to get everything together, the hammer had to be placed in roughly the half cock position to allow the sear to reset correctly into the hammer. I don't know if this is a one-off, or representative...but it was at least present on this one. I didn't investigate further to determine they why of the glitch. Again, not a deal breaker for me, but something to be aware of just in case anyone else runs into it while detail stripping the frame.
None of the small parts were MIM. Neither did I find any evidence of investment casting. However, I also didn't see any evidence of machining or finish machining.
Puzzled, I looked as closely as my failing eyes would allow, and I did see some light surface porosity, and...after pondereing on that for some time after we parted company...I have to suspect that the parts are sintered. I didn't inspect the frame closely, so it's possible that it was also made via sintering. I assume that the slide was cut from barstock. Hopefully, the lessons learned by Essex and Thompson Auto Ordnance and relearned in the early days by RIA concerning cast slides weren't lost on Tisas.
Sintering is a viable process. Like MIM, it's powder metallurgy. It differs from MIM in that the material is heated to the lower critical line...just short of liquefaction...and formed under pressure to fuse the material. Post-64 Winchester Model 92/94 receivers are sintered, and I've never heard of any problems from them that could be related to strength or durability.
With MIM, the powder is mixed with a binder...injected into a mold...and "cooked" to burn off the binder and allow the powder to fuse into a solid part. The problem with MIM is that it's not suited to high impact or shearing stresses whereas sintering is at least adequate...the proof of which is all the post-64 Winchester carbines in service. Whether it would hold up to sustained, heavy use remains to be seen, but it's a sure bet that it'll be better than investment casting.
Overall fit and finish are very good to excellent. If I was in the market for a new 1911 pattern pistol, I'd certain;ly tale a long, hard look at the Turkish offering.
On disassembly, the plunger assembly launched out of the plunger tube because the spring didn't have the required dogleg kink. I corrected it on the spot.
During reassembly, the slidestop presented a little problem due to the rear angle of the lug. I didn't correct that, but it's an easy fix should Mac decide to tackler it, and not a major problem to use a credit card to push the plunger back into the tube if he doesn't.
A little more extractor deflection than I like to see, but if it doesn't cause a problem with feed/RTB, it can be ignored, or easy to correct if it does.
The hammer hooks weren't bearing evenly on the sear crown. That became evident when I lightly boosted the hammer and the trigger immediately went from about 6-7 pounds to double that. More light boosting had it on its way to being equalized, and I'd say that a couple hundred rounds to let everything wear in and seat and Mac will end up with a clean 5-5.5 pound rollout trigger...perfect in my world for a duty gun.
As I said...minor gripes.
The oddest issue popped up when reassembling the frame. With the hammer full forward, the sear feet were kicked out, making installation of the mainspring housing impossible when the sear spring was installed. In order to get everything together, the hammer had to be placed in roughly the half cock position to allow the sear to reset correctly into the hammer. I don't know if this is a one-off, or representative...but it was at least present on this one. I didn't investigate further to determine they why of the glitch. Again, not a deal breaker for me, but something to be aware of just in case anyone else runs into it while detail stripping the frame.
None of the small parts were MIM. Neither did I find any evidence of investment casting. However, I also didn't see any evidence of machining or finish machining.
Puzzled, I looked as closely as my failing eyes would allow, and I did see some light surface porosity, and...after pondereing on that for some time after we parted company...I have to suspect that the parts are sintered. I didn't inspect the frame closely, so it's possible that it was also made via sintering. I assume that the slide was cut from barstock. Hopefully, the lessons learned by Essex and Thompson Auto Ordnance and relearned in the early days by RIA concerning cast slides weren't lost on Tisas.
Sintering is a viable process. Like MIM, it's powder metallurgy. It differs from MIM in that the material is heated to the lower critical line...just short of liquefaction...and formed under pressure to fuse the material. Post-64 Winchester Model 92/94 receivers are sintered, and I've never heard of any problems from them that could be related to strength or durability.
With MIM, the powder is mixed with a binder...injected into a mold...and "cooked" to burn off the binder and allow the powder to fuse into a solid part. The problem with MIM is that it's not suited to high impact or shearing stresses whereas sintering is at least adequate...the proof of which is all the post-64 Winchester carbines in service. Whether it would hold up to sustained, heavy use remains to be seen, but it's a sure bet that it'll be better than investment casting.
Overall fit and finish are very good to excellent. If I was in the market for a new 1911 pattern pistol, I'd certain;ly tale a long, hard look at the Turkish offering.
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