doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Drop at comb ......DAC

So, I know what DAC is, but I, for one, do not know at what point along the comb the measurement is taken. Is it just behind the nose, is it where the cheek (of the seller) impacts the comb, is it at some pre-determined point between the nose and the heel?

If there is standard for this measurement I would really like to know what it is. When I review buttstock dimensions on a gun I pay close attention, because I am a shooter .......... not a collector who wants safe queens.

Thanks, SRH

I suspect it would pay to ask the seller the point where they measured it....

Just saying.

B-B = DAC
A-A = DAH
Measurement in the middle of the comb may be called "drop at face"

It's rare for you, but that is a good point. But, the other question I asked is........ is there a standard?



And, what does "in good proportion" mean, Doc?

SRH

It goes on to describe the drops, I find 1&1/2 x 2&1/2 right for "most" people. Kinda why the average guy can shoot a M12 or an 870 pretty well.

Sorry Stan. The post-1913 order form only specified DAH and LOP so the DAC was in "good proportion"



Hunter Arms standard stock with a hard rubber buttplate was 14 1/4" LOP from the front trigger, 1 5/8" DAC, 2 3/4" DAH, with a positive/down pitch of about 2 1/2" for a 30" barrel gun

Monte Carlo dimensions from Pigeon Shooting by Capt. A.W. 'Bluerock' Money, 1896. B1-B1 was called "drop at monte carlo"

Stan,
That's something I've often wondered myself.
According to Brian Bilinski at Fieldsport in Traverse City, he specifies drop at face taken midway between the nose of the comb and the heel in addition to the typical dimensions of drop at comb and at heel. My "magic" number happens to be 2".
Hope this helps.
Karl

Didn't mean to put you on the spot, Drew. But, the phrase "in good proportion" does sound more like advertising hype than detail, doesn't it? I've never seen any evidence of a standard, but that doesn't mean it doesn't exist..

SRH

I had my stock fittings measurements done by Brian Bilinski as well.

On my fitted stocks, that measurement is from where my cheek touches the comb to the plumbline of the trigger.

Stan is correct if you have a long neck or a Shortneck or you cant your head or you tilt it forward, it effects the drop at comb that the shooter experiences.

What he�s really doing is lining his eye up behind the rib by head movement.

We seldom talk about how fat the stock is where the cheek intersects the comb, because in addition to the up and down measurement, there is also a side to side measurement.

To shoot really well, the shotgun comes up to the face and you don�t have to move your head. But, if you shoot a lot of different shotguns, that ain�t gonna happen.

Back when I was concerned about it, I would just try to get the drop at comb measured along the centerline of the stock close enough, Nothing too outrageously different than what I require, and I just worked from there.

Ultimately, I can adapt to about half an inch too much, but not an inch.
There�s just too many of the old guns that interest me, that what came from the factory was way different than what I shoot well, so if I was going to enjoy them, it was either turn them into something that they weren�t, or just except that I was never going to shoot them great.
I embrace my mediocrity spread out over a bunch of guns.

I once read Yardley's book entitled "Gunfitting", but cannot remember whether or not anything in it was in reference to this.

SRH

Karl now you can join the Stan's Lost Wanderers Club...

Quite the hobby hanging out on several internet boards all day just sitting around wondering what wonder to share todAy.

Makes me wonder what wondering Stan will share with us next.

While we are on the topic. I don't know who first named the "parallel comb", but an (almost) straight stock was promoted on the Winchester 1897 "Tournament" grade, from Sporting Life June 26 1909
DAC 1 3/4�, DAH 1 13/16�



and Model 12 Tournament Gun; March 28, 1914 Sporting Life

Much rather read and consider Stan's wonderings than your petty sniping from the sidelines.

I was under the impression that the drop at the point of the comb was the "Standard". Every old catalog which I have seen when guns could be had to order gave a diagram for listings measurements showed this as the place for drop at comb. On the vast majority of guns the line from comb to heel was a straight line. A few exceptions were, of course, the Monte Carlo, a German "Swineback which W WGreener called his "Rationale" Stock.

...

...

I have always measured DAC as 7" from the butt, which is where my cheek hits the wood. It is a backhanded way of assimilating the vagaries of the neck and face, but it puts things where they belong.

What I don't understand is defining DAC as a distance from the trigger. To me, that is very independent of line-of-sight, and seems geared more toward keeping the thumb out of the face than dialing in a line of sight. Did I miss something?

In cataloguing my stock guns I quote drop at heel, face and comb.
The definitions for the UK trade heel and comb are straight forward:
Heel, the drop from the line drawn from the muzzle end of the top rib and the 'shield' between the fences, measured at the very extreme end of the stock before it falls away to form the butt.
Comb, the drop as above to the point at very front of the stock comb before it drops away to the thumb.

It is important to realise that many guns have a 'shield' that is sunk between the fences so the common method of measuring drop by placing the gun upside down on a flat surface only gives an approximate value. To get the drop measurement that the eye sees one needs a drop gauge that is no wider than the 'shield' and is cut away to sit on the rib just behind the bead, not on top of the bead.

Face is much more variable. I define it as the drop as above, 8" LOP from the front trigger on a double trigger gun. This is just where I set it, others will have different definitions.

Another little understood measurement is LOP to 'bump'. This may be the same as LOP to 'heel' but not if the stock has a butt that has a bump just below the heel. The LOP to heel is the measurement to where the angle in formed between the comb and butt. The LOP to 'Bump' is the LOP to the longest part of the stock at the bump. In most classically shaped gun butts, the LOP to heel will be around an 1/8" shorter that LOP to bump.

Thanks (almost) all, for the contributions.

It seems there is a specific place to measure DAC, but not DAF. The only way to get a meaningful number for DAF would be to know how many inches it is away from either the front trigger or the butt for you, as Ithace5E said, then ask the seller to provide that measurement.



How many boards you been kicked off of, or suspended from, F rank C ox, or how many times total? Me ....... zero.

SRH

Stan,
In my previous post I mentioned that Brian Bilinski at Field Sport explained to me that the DAF he measures is midway between the nose of the comb and the heel. The shotguns there that measured 2" DAF fit me well, therefore my "magic" number providing the length of pull and cast off are correct.
Karl

Thanks, Karl. Food for thought.

SRH

Drew's diagrams haven't changed much over the years. DAC is usually measured at the start of the comb even today by most.

Not a huge fan of Don Currie but



#2 is standard for DAC measurement from all the books I have on it.

Currie's diagram does bring up a good point, that there are a lot of other measurements to gun fit. #3 is Drop at Face and Dave Erickson gave a great example of that. He shot that custom ordered Iside well before shaping and expect he will now be even a stronger force to be contended with. Oh just freaking great

Comb thickness was also mentioned and has a huge impact IMO. 870's and model 12's were mentioned but the Ithaca 37 field has no pitch, and no cast. And a very thin comb. I shoot them extremely well.

Surprised that the parallel comb that Drew also mentioned hasn't taken off more than it has over the years. Didn't realize it has been around that long. On my target shotguns I normally set them up to be as parallel as possible. With a 4 way adjustable comb and using offset. Even on my 32" Dickinson Sporting gun.



Still a work in progress and sometimes regret selling my 682 Gold target gun. Sometimes..

I can pick up my 20 ga. Winchester 23 and usually hammer targets with factory dimensions which are different than most of my other target and hunting guns. As long as I don't think and use swing through.

Metrics can be measured with consistency. Measure at the start of the comb, most do. But there are a lot of other measurements involved IME. It is complicated...

Well not really, see the bird shoot the bird. But it sure helps if the gun shoots where you are expecting it to and are used to.

Excellent point, CZ. Which, IMO, makes cast somewhat variable. I know that I can shoot some guns with no cast fairly well, and I can shoot some with at least 1/4" of cast fairly well. The X factor, as you point out, is the thickness of the stock.

Too thick a comb is much worse than too thin, IMO. A very thick comb only works for me if there is some cast. Within limits most can learn to adapt pretty well to a too thin comb, or a little too much drop, by cheeking the gun "lighter". We look at the bird/clay when shooting, but the rib is in our line of sight, just out of focus. Some people seem to have learned to make the small corrections to line up with the rib instantly, not ever looking at it in focus, and without much conscious thought. I shoot a variety of shotguns pretty well, with varying amount of drop. The critical things for me are ........... (1) it can't be stocked so high that I have to cheek it hard to get it to shoot nearly flat, (2) and it can't be so thick in the comb that I can't line up on the rib.

I have a friend who can pick up almost any shotgun and shoot it well. Some people are just better at instantly adapting than others.

Could it be because he's a do'er and not a wonder'er ?

Good point Toby...thanks for the hands on contribution.

What contribution are you in disagreement with ?

Some shooters prefer a gun with a DAF that puts their eye directly in line with the beads. Others prefer to be well above the beads. Some shooters shoot both styles well, even though there may be a quarter inch or more difference in the DAF. Those who collect shotguns by the dozens had better learn to shoot both ways. The truth is that most shooters who are hunters don't have to shoot a high average to be happy. If you are shooting for money, shoot the gun among your many that you shoot the best. No fuss, no muss.

You're the only one here who would have to ask that. Think about it, if that's not too taxing for you. Who contributed the least to the discussion? Bingo!

SRH

Thought you said I made good point Stanley.

Don't get the big hEad.

You all know more about this than I but the discussion was fascinating. I picked up my 16 gauge muzzle loader 1847 Reilly 5512 (1847) today and stopped by the shooting center...hit 12 out of 20 sporting clays tried, 6 from each barrel and the gun felt great (Fg powder, 70 grains, 1 oz 7.5 lead shot using the "Skychief" load). (Not great shooting...just satisfying for a new gun and the first muzzle loader I've shot in 40 years).

I was wondering why it felt better than the first and (only time so far) I've shot the new side lever 16 gauge Reilly 27853 (1887). I started wondering if I like more drop (or was I just having fun with a newly fixed hammer on the muzzle loader?)

Here are the two guns. 5512 has a much thicker comb. They look very different in profile. Surprisingly both have a comb drop of 1 5/8". Strange.

Don't discount the dynamic balance of the gun. For example. I find I need to shoot with the same barrel length all season or my shooting falls off a cliff. Furthermore, even given the same barrel length and very similar stock dimensions, some guns just don't mix.
On closer examination I have found that the simplistic balance point of the hinge pin is misleading. A gun can balance on the same central point but due to the distribution in each half of the gun, the gun has a very different dynamic. Depending on one's shooting style, this can make a big difference: if one shoots a steady swing, a distribution of weight to the extreme points of the gun can help maintain your swing. In contrast, a habit of fast application of forward allowance may be aided by centralised mass assists in fast acceleration of the barrels.
Also, I referred in my previous post to the difference that a sunken 'shield' can make to the effective POI of a gun that one might assume to have similar stock dimensions. For example, I have a Blanch hammergun with a sunken rib AND a very sunken 'shield' which gives the impression when mounted of a very high shooting gun but when one packs up the 'shield' to a normal height (in relation to the bore axis) one finds that the gun should shoot as one which measures up as much lower shooting
Quite why this was done is unknown but I guess it was the a preference of the customer to have a gun that shows a lot of rib whilst still shooting quite flat.