Effects of J-lock

[HFV]

Why do shooters hate the dreaded J-lok on Rem 700 bolt shrouds?
How does it effect accuracy ,, or does it?

 

[wapiti25]

you need to look at the firing pin and spring, you decide

 

[CatShooter]

Why do shooters hate the dreaded J-lok on Rem 700 bolt shrouds?
How does it effect accuracy ,, or does it?

Aside from the "Big brother" aspect of it, and the uoogly factor - the lock had a tendency to drift and lock itself, and the bolt would be locked when you lost the key a year before, so you couldn't shoot your rifle.

Other than that - it was a good design - the pin itself, weighed about 450 grains, whereas the standard pin weighed about 850 grains... so the lock time was half of what the standard pin was.

Some guys got their undies in a knot because the spring looked curly, because the pin was thinner (to make it lighter)... and invented a million reasons why that was bad.

But no 24 pound spring that is ~0.4" in diameter and 5" long, can stand straight on it's own... ALL firing pin springs rub on the pin shaft or the bolt bore - it is impossible to avoid and it does nothing to slow the pin or effect accuracy.

If you have a "J-Lock", you can get new shrouds from Brownells, without the lock.

 

[Dans40X]

ISS/J Lock vs Std firing pin parts are NOT interchangeable.

The only piece in the equation that interchanges between the two is the striker/cocking piece to pin 3/32"D X 7/16"L cross pin.
If your cross pin is aftermarket & a dowel pin - replace it w/ drill rod as the dowel pin is too hard & will break.

 

[LHSmith]

An easy check on accuracy difference is to switch out the FP assembly on a proven full race Benchrest 700 between a J-lock, a Speedlock and a standard Remington non-J-lock. the standard Remington non- J lock wins hands down. There is a reason Stolle action's fire control and Remington's are very similar in spring weight and FP weight and design....proven through years of competition.
One article in Precision Shooting magazine (there were several on the subject) by Norman Johnson showed that just to insert the snaky J-lock spring in the bolt body took 3 pounds of force, and testing revealed it actually caused a variable resistance against the inner walls of the bolt.
The standard Rem. spring just slides into the bolt body effortlessly. I'd rather the spring ID rub against the smooth FP shaft, than the spring OD rub against the corncob finish of a typical factory Rem bolt ID. Note that the snaky spring actually rides both the FP OD and the bolt body ID.
If the snaky spring and skinny FP design worked so well why did Remington abandon it?

 

[CatShooter]

One article in Precision Shooting magazine (there were several on the subject) by Norman Johnson showed that just to insert the snaky J-lock spring in the bolt body took 3 pounds of force, and testing revealed it actually caused a variable resistance against the inner walls of the bolt.

I owned a J-lock bole rifle for a time, and there was no problem inserting the pin assembly.

The standard Rem. spring just slides into the bolt body effortlessly. I'd rather the spring ID rub against the smooth FP shaft, than the spring OD rub against the corncob finish of a typical factory Rem bolt ID.

I own a bunch of Remingtons, and none of the bolts have a "corn cob finish"... exactly how does one drill a hole with a corn cob finish - is it a special drill?

Note that the snaky spring actually rides both the FP OD and the bolt body ID.
If the snaky spring and skinny FP design worked so well why did Remington abandon it?

They abandoned it because of the over reactions of the public - it was not worth the cost of trying to over come ignorance and rumors.

 

[LHSmith]

^^^^^ No ignorance or rumor......just simple fact. It doesn't take a mechanical engineer to see how the J=lock FP was not conducive to consistent ignition. Must I dig up more articles proving it was a flawed design?

 

[Ledd Slinger]

I use the PT&G Speedlock assemblies and shrouds. Usually get the fluted firing pin for faster lock time. For $30-some bucks, you can't beat 'em.

As for the J-lock, I hate the idea that it can be locked very easily with other tools or in some cases excessive recoil, but can only be unlocked with the key. Not a fan of anything that could possibly disable my firearm. Even if I used a J-lock and meant to lock it, went to the range and happened to forget the key, I'd be pretty upset. Be as bad as forgetting your bolt...not that I've ever done that :

Anything Remington has changed from the original Model 700 design has been for the worse. Especially the triggers.

 

[CatShooter]

Be as bad as forgetting your bolt...not that I've ever done that :

Yeah... I've never done that either :

 

[Dans40X]

Being smarter than the equipment that you are working on/with-
The ISS/J Locks can be activated w/o the key but require the key to unlock by depressing the detent ball in the shroud.
If needed at a later date(to detour inquisitive children) the ISS/J-Lock firing pin shank can be rotated 180 degrees in the striker/cocking piece to deactivate the lock feature.

The initial design was an interim idea to detour the law suites from idiots never cleaning the standard trigger groups or adjusting them improperly & of course steering the rifle w/ finger on trigger shoe shooting themselves/sibling & alike.

A lighter firing pin w/heavier mainspring can not,will not reduce lock time.PERIOD.
It only makes bolt manipulation harder to accomplish & they will break.

 

[ebb]

My ultra mag came with one of the very early J locks, It didn't even have a spring that had round wire it had a flat wire spring. It looked like it would cut shavings from the inside of the bolt. When I described it to the gunsmith that chambered the new barrel, he said don't send it with the gun if you want it I will throw it away.

 

[fredo]

I use the PT&G Speedlock assemblies and shrouds. Usually get the fluted firing pin for faster lock time. For $30-some bucks, you can't beat 'em.

I have Gre-Tan F/P assemblies on a few rifles and like them alot.
Tried a PT&G Speedlock recently & the F/P literally snapped in 1/2 on me.

Back to tried & true Gre-Tan stuff for me...