Variances in chokes?
 

I did some checking with an inside caliper of the chokes on my 1900 12 ga. Parker tonight. I compared the Parker chokes against my Invector+ chokes from my Browning Citori Lightning.

The Parker letter I recieved today said the barrels were choked Full & Full.
Visually you can see they are not the same, the guy i bought it from said they were mod. & full.

The Parker right barrel chock is just a hair tighter than the Improved
Modified invector+.

The Parker left barrel is almost as tight as the X-full turkey
invector +.

Thoughts please.

Mike :-)

You really can't measure a choke properly (or at least an older SXS choke) with a caliper. Choke constriction is not a static measurement but the amount of constriction as compared to the i.d. of the bore about 6" back from the muzzle. Even this description is a bit too simplified because an original Parker choke is more complex than a simple cone.

They only way to really find out what any shotgun is choked is to carefully pattern it by shooting it and counting the holes in a 30" circle at 40 yards (many times).

Measurements are not meaningless but they don't tell you the full story. You could have a Parker that shoots full and full and the barrels might have 32 and 38 thousandeths of constriction.

Each barrel reacts diffently, each gun reacts differently. It might shoot extra full with 8's and modified with 6's. There are a lot of factors at play that cause this.

One the great things about Parker's is their chokes and ability of the tight chokes to really reach out and touch them. Parker put a great deal of effort into barrels, regulating them and shooting them to get desired performace. Choke perforamce is one the BIG reasons why I think a well worn Trojan is better than a lot of brand new anything.

So what your saying is Parkers were not a cookie cutter produced gun.
So about how many times was the average Parker pattern fired and honed
till they had it right? 40 yrds. was mentioned as the patterning range, what
Size shot did they use in this test patterning?

When it comes to choke performance there were no cookie cutters, at least no untested cookie cutters. A PGCA letter may give you information on what the chokes were to be and sometimes they contain information regarding shot size and shot weights used. 12ga guns were often patterned with straight no. 7 shot.

Choke performance is one of the great joys of shooting a Parker in the field.

It may be as simple as someone has openned up the right barrel, as well. Two GH guns from the 05 era I have, had their "Full" dimensions right at .040". You need to measure the bore and then the constriction. A straight section in the muzzle end of the choke, often is an indicator someone may have openned a choke.

Chuck,
Actually a 1/4" to 3/8" straight at the end of a Parker choke is pretty normal. Austin has posted here and in the Parker Pages diagrams showing the shape Parker used to achieve the wonderful patterns these gun produce. Of course modern ammo shoots and patterns differently then that which the factory used so as Pete says you really need to pattern each gun with the ammo you intend to shoot to know what the gun will do.

The choke measurement comparison between the Browning and the Parker is of no consequence because the bore diameters may be different by many thousandths. Parker bores were not all the same, nor were the ranges, target dimensions, shot sizes, or shot weights used in the factory patterning of the guns.

Read the "Winter Project" thread on the Hammer Gun section of the forum for a little more information on Parker chokes and patterns.

And, depending on where the shot was sourced, shot size o.d. was not necessarily consistent between shot makers so the pellet count may vary somewhat especially between then and now with plastic shot cups.