Colt Versus Colt 45s: Series 70 Competes Against the 1991A1

Some would say the Colt 1991A1 and the Colt Series 70 are as different as night and day. The purpose of this test was to determine how dissimilar these two self-defense guns really are.


When other makers put market pressure on Colt by introducing a bevy of inexpensive 1911A1 handguns, Colt responded with the 1991A1, replacing the expensive Colt high-polish bluing with a matte finish. Walnut grips were deleted in favor of plastic or rubber, although recent Colt 1991A1 production features good-quality wood-grip panels. Features these more affordable 1991A1-Colt pistols kept were the flat mainspring housing and long style trigger of the original 1911 handgun. The usually accepted justification for having a flat mainspring housing is that it is easier to fit a custom-grade beavertail safety. The 1991A1 also featured a scalloped ejection port and sights that are an improvement over GI-model handguns. There was no full-length guide rod, so the pistol was easily field stripped. In the eyes of many, Colt successfully turned out a basic 1991A1 that was affordable for those who would prefer to own a Colt rather than other brands.

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However, there was a bone of contention concerning the 1991A1. If a company is going to make institutional LE or other agency sales in this century, the pistol must have a firing-pin lock or drop safety. The Series 80 firing-pin block used in the 1991A1 adds four parts in comparison to the Series 70. The parts are the frame-mounted trigger-bar lever and plunger and the slide-mounted firing-pin plunger and driving spring. Simplicity must be better for reliability, some said. The firing-pin block keeps the firing pin in place until the trigger reaches its rearward travel maximum and releases the firing-pin block and the firing pin. Also, shooters soon learned that care must be taken in disassembly and reassembly with this design so that the plunger is not damaged.

Why was the firing-pin block introduced? If the 1911 handgun were dropped on the muzzle from a sufficient height, the inertia of the firing pin could take a run forward against spring pressure and crack the primer, firing the pistol. This problem is not unique to the 1911; many pistol designs have been updated with firing-pin blocks. Some makers solve the problem with a lightweight firing pin and heavy-duty firing-pin spring. In fact, Para Ordnance (now Para USA) and SIG use the Series 80 firing-pin lock by license. Once Beretta and SIG incorporated the firing-pin block in production, competitors had to follow the same path in order to compete in the law-enforcement market. Even though the majority of accidental discharges are negligent rather than accidental and are caused by shooter error, the firing-pin block is here to stay in the 1991A1. And therein was the problem for many Colt fans.

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In short, they feel that Colt ruined the trigger action by adding the drop safety, and that the resulting Series 80 designation was inferior to the Series 70. Others felt that the assembly could lead to problems if it malfunctioned. The fact is, a Series 80 design may malfunction if a trigger job isn’t done correctly or if a lightweight trigger is added to the pistol and not adjusted correctly. In any case, many Colt shooters believe the Series 70 is a better set-up than the Series 80 design.

The way we see it, the only way to determine if the Series 80 design is inferior to the original Series 70 design is to shoot them side by side with a team of testers who love to nitpick. So we acquired a high-grade current-production Colt that is similar to the original Series 70 — that is, a pistol with good finish and excellent fitting but without the firing-pin block — and shot it against a 1991A1 Series 80 pistol. Each pistol was supplied with two Colt magazines. We normally use a good supply of 1911 magazines during testing, but to thoroughly proof each pistol, only Colt factory magazines, as supplied with the pistol, were used. Most important, there were no malfunctions of any type with either handgun.

So, beyond that, is it worth it for Colt fans to go to the gun show, cash in hand, searching for a Series 70 pistol, or for non-Colt shooters, a similar 1911 handgun without the firing-pin block? Side-by-side shooting determined just how great an advantage, if any, the Series 70 has over the 1991A1 with its Series 80 internals. Here’s what we found:

Colt 1991A1 O1991 45 ACP, $745

The first character in the model number is a capital “O” and not a zero. The price listed is from, but we also found this model in stock at for as low as $717 cash price and for $725 at Our test gun was purchased very lightly used and appeared unfired. The grip safety indented in a positive manner, the magazine release worked properly, and the trigger compression, while heavy at 7.0 pounds, broke cleanly. We were perhaps expecting a slightly lighter break because one of our tester’s 1991A1 breaks at 5.0 pounds out of the box.

In our sample, we noticed little play in the frame-to-slide fit. The barrel bushing was finger tight, and because there is no full-length guide rod, the pistol is easily field stripped without tools. The finish was dull but even. The grips were OK, but unlike some of the earliest examples of the 1991A1 grips, these supported the plunger tube. An examination of the feed ramp pointed out similarities in each pistol. Each had the requisite 1⁄32-inch gap between the two parts of the feed ramp, the frame section and the barrel section. This ensures feed reliability. Feed ramp polish seemed equal. The 1991 pistol featured a lowered or scalloped ejection port, an upgrade, we believe, to the original-style ejection port of the Series 70 Colt. In handling the Series 70 side by side, we noticed spent cases ejected just fine, but during administrative handling, it was more difficult to eject a loaded cartridge than with the 1991A1. An important consideration with the Series 70 is to never use a shock buffer if the pistol is destined for personal-defense use. With the shock buffer, the slide will not retract sufficiently to clear a loaded cartridge from the chamber if the magazine is locked in. In the event of a dud round, this could leave one in a predicament. So, all in, the 1991A1 slide window is superior in this regard, in our opinion.

Another advantage of the 1991A1 is the cut-out in the frame. Originating with the 10mm Delta Elite, this modification strengthens the frame, although it would take many heavy loads to prove the advantage. Over the years, our shooters have seen many 1911 handguns with cracked frames, although most still functioned fine. The usual culprit is the owner shooting heavy “pin loads” and doing lots of shooting.

During the firing tests, the 1991A1 never failed to feed any type of ammunition. The combat firing test, accomplished primarily with Winchester USA 230-grain ball ammunition, showed that this handgun, like all 1911 handguns, is fast from leather and offers excellent first-shot accuracy. We drew from an S&S Belt Scabbard holster with both handguns. This scabbard exhibited a good balance of speed and retention. During the range work, raters ventured into subjective comments that are more difficult to quantify than firing for accuracy. But this is what the test was all about. We fired the pistols together, one string with one pistol and another string with the other, and it seems the targets bore out their observations. The long trigger and flat mainspring housing were not as friendly to those with small hands, and the flat mainspring housing seemed to result in lower hits on the target. It took a conscious effort to accommodate this, and this tendency was more noticeable after firing the Series 70.

We took great pains to focus in on the 1991A1’s trigger action. It received favorable comments, being described as smooth and free of grit creep or backlash. It felt lighter than its scaled 7.0 pounds. Reset was rapid. In firing for accuracy off the benchrest, the 1991A1 gave good results, including a 2.4-inch 25-yard group with the Cor-Bon 230-grain JHP +P, a powerful defense cartridge. All groups were not as small, probably attributable to the heavy trigger.

As a utilitarian handgun to defend the home and person, the Colt demonstrated good performance. We feel that the gun’s characteristics on target would also give the user more than a little satisfaction and real pride of ownership. We originally intended to rate the gun down based on a heavy trigger compression, but then considered the scalloped ejection port and the frame stress relief slot.

Our Team Said: When field-stripping the pistol for images, it took two hands to release the firing pin to remove the firing-pin stop for images, with one tool pressing the firing-pin block to release the firing pin and the other depressing the firing pin to release the firing-pin stop. This was more complicated than the Series 70. However, on reassembly, the firing pin was pressed in and locked. There was no danger of it taking flight. Simply slip the firing-pin stop in and press the firing pin in. Different, but probably slightly easier, than the Series 70, in our estimation.

Colt Series 70 O1970A1CS, $953

This is Colt’s answer to those clamoring for a Series 70 pistol. The price as listed was from for an in-stock product. Cash price was $925, so the cash-price-to-cash-price margin from the same retailer puts the difference between the two guns at $208. So it is safe to say, on average, the Series 70 pistol will set you back $175 to $200 more than the 1991A1.

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Our examination of a NIB version of this gun was that it was nicely fitted and finished. The flats of the slide were darker than the polished-blue frame and side of the slide, and the result is an attractive handgun. Trigger compression was smooth at 4.75 pounds and crisp. The sights were identical to the 1991A1. The pistol did not feature a lowered ejection port, as mentioned, and would not have the appearance of the original Series 70 anyway, so consider this subject when purchasing either Colt for tactical use.

Elsewhere, the Series 70 pistol was appointed with nicely checkered wooden grips. These grips feature the double-diamond pattern that makes for greater strength where the grips are attached to the grip bushings. The Series 70 was finished in a manner more similar to the production Colt pistols of the 1960s than the original Series 70. A member of the test team has produced two books on the 1911, and he states without reservation the new gun is a better pistol than the original Series 70 in fit, finish, and performance.

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This Series 70 featured an arched mainspring housing and short trigger. The arched mainspring housing seems to hold the muzzle higher, and this resulted in faster combat hits. The pistol did not demand a break-in period, as was common with original Colt pistols. The slide stop was noticeably tighter than on the 1991A1, and so was the barrel bushing. The firing pin stop was not only tight, there was a dimple at the base to prevent the slide stop from falling. This was once a common problem with well-worn GI pistols. We have never seen this on another factory gun. The various 1991A1 and Series 80 pistols do not have this dimple.

In combat shooting, most of our shooters said that the arched mainspring housing gave better control than the 1991A1, and combined with a short trigger reset, the pistol ran better in rapid-fire strings. There was a well-defined shorter travel to press the trigger and to achieve reset. The consensus is that the long trigger and flat mainspring housing are more target features than combat features. All in, the Series 70 pistol exhibited high-grade fit and finish and feeds modern ammunition without hesitation. Good sights make it easy to align on target as well.

In firing off the bench, few shooters realize that good quality grips (stocks, grip panels) will help direct fire and keep the hand in place to center the sights. The stocks of the Series 70 do so better than the 1991A1, in our view. When firing off the bench, however, the 1991A1 gave the impression of greater comfort. Perhaps the arched housing of the Series 70 drove the palm into the grip safety tang? It wasn’t a huge deal, but the sensation was something that the raters agreed upon.

The Series 70 was narrowly the more accurate handgun, with a best group of 2.2 inches with the Asym 185-grain JHP. Even after fitting Bar-Sto Precision grips on the 1991A1, the consensus remained the same.

We have to stress that the Series 70 isn’t a true reproduction of earlier models, but is instead a considerably improved pistol over the original. As an example, the barrel bushing isn’t the collett type and proved slightly tighter than the 1991A1. The action does not have a half-cock notch, as was the case with the 1970s Colt. The new Colt action, beginning with the Series 80, uses a shelf in the hammer rather than notch. This shelf will still catch the hammer if you slip while cocking the pistol. If the pistol is slightly cocked and the trigger pressed, the hammer will fall from this shelf, but not fire. In the original action, there was a condition called false half cock, which would allow the hammer to fall from half cock if the trigger were pressed. We are glad that the Series 70 has the new action.

When field-stripping the pistol, we noted that the firing pin is a Series 80-style piece, with the notch for the firing pin block. This makes sense for Colt, so be certain when ordering parts, you differentiate between an older Series 70 and the new one.

Our Team Said: The current Series 70 is not a copy of the original Series 70. The grips are superior, and so are the sights. The Series 70 in its current version is a nice carry gun, accurate, reliable and pleasing to look at. In fast combat shooting, it seems to have an advantage over the 1991A1. The 1991A1 costs less, is equally reliable, almost as accurate, and features a scalloped ejection port. The firing-pin block was not proven in our tests to be worth worrying about, and may be a good idea in a true hard-use handgun. In our view, the 1991A1 is the better buy as a workhorse handgun, and it would be the pistol to go to war with today.

But the Series 70 caters to a discriminating crowd, and if you consider it closely, the no-frills shooter is paying more for the Series 70 to have some things deleted. Our shooters gave the nod to the Series 70 in this head-to-head match-up.

Written and photographed by R.K. Campbell, using evaluations from Gun Tests team testers.


  1. Bought a pair of 1991A1s in the 90s and I love them. They are both accurate and reliable. Even to this day, with about 2000 rounds through each of them. I like my Beretta and Glock as well. But there’s something about the Colts the others don’t seem to capture. I can’t quite put my finger on it. Who knows, maybe I watched too many war movies-lol.

  2. I have a colt m1991a1 and I’m wondering how safe it is to use the +P ammo. I read somewhere standard ammo is around 21,000 psi and the +P ammo is about 23,000 psi. Will the higher pressure of this ammo eventually take its toll on this pistol?
    And if it’s okay to use +P ammo, how about the 450 SMC ammo by Doubletap? That ammo is like +++P. I saw somewhere on youtube that if your pistol can handle +P ammo then it would be okay to use 450 SMC ammo as wll. However, I read somewhere the pressure from this ammo is somewhere around 32,000 psi. Is this ammo safe to use or will it eventually damage my pistol as well?


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